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<title>4.&nbsp; Database Support</title><link rel="stylesheet" href="css/docbook.css" type="text/css"><base href="display"><meta name="generator" content="DocBook XSL Stylesheets V1.72.0"><link rel="start" href="manual.html" title="Apache OpenJPA 2.0 User's Guide"><link rel="up" href="ref_guide_dbsetup.html" title="Chapter&nbsp;4.&nbsp; JDBC"><link rel="prev" href="ref_guide_dbsetup_sqlconn.html" title="3.&nbsp; Runtime Access to DataSource"><link rel="next" href="ref_guide_dbsetup_isolation.html" title="5.&nbsp; Setting the Transaction Isolation"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">4.&nbsp;
Database Support
</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="ref_guide_dbsetup_sqlconn.html">Prev</a>&nbsp;</td><th width="60%" align="center">Chapter&nbsp;4.&nbsp;
JDBC
</th><td width="20%" align="right">&nbsp;<a accesskey="n" href="ref_guide_dbsetup_isolation.html">Next</a></td></tr></table><hr></div><div class="section" lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a name="ref_guide_dbsetup_dbsupport"></a>4.&nbsp;
Database Support
</h2></div></div></div><div class="toc"><dl><dt><span class="section"><a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbdictprops">4.1.
DBDictionary Properties
</a></span></dt><dt><span class="section"><a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbsupport_firebird">4.2.
FirebirdDictionary Properties
</a></span></dt><dt><span class="section"><a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbsupport_mysql">4.3.
MySQLDictionary Properties
</a></span></dt><dt><span class="section"><a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbsupport_oracle">4.4.
OracleDictionary Properties
</a></span></dt><dt><span class="section"><a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbsupport_sybase">4.5.
SybaseDictionary Properties
</a></span></dt><dt><span class="section"><a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbsupport_delim_id">4.6.
Delimited Identifiers Support
</a></span></dt></dl></div><a class="indexterm" name="d0e20134"></a><a class="indexterm" name="d0e20137"></a><p>
OpenJPA can take advantage of any JDBC 2.x compliant
driver, making almost any major database a candidate for use. See our officially
supported database list in <a href="supported_databases.html" title="Appendix&nbsp;2.&nbsp; Supported Databases">Appendix&nbsp;2, <i xmlns:xlink="http://www.w3.org/1999/xlink">
Supported Databases
</i></a> for more
information. Typically, OpenJPA auto-configures its JDBC behavior and SQL
dialect for your database, based on the values of your connection-related
configuration properties.
</p><p>
If OpenJPA cannot detect what type of database you are using, or if you are
using an unsupported database, you will have to tell OpenJPA what
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/DBDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.DBDictionary</code></a> to use.
The <code class="classname">DBDictionary</code> abstracts away the differences between
databases. You can plug a dictionary into OpenJPA using the
<a href="ref_guide_conf_jdbc.html#openjpa.jdbc.DBDictionary" title="6.2.&nbsp; openjpa.jdbc.DBDictionary"><code class="literal">openjpa.jdbc.DBDictionary
</code></a> configuration property. The built-in dictionaries are listed
below. If you are using an unsupported database, you may have to write your own
<code class="classname">DBDictionary</code> subclass, a simple process.
</p><div class="itemizedlist"><ul type="disc"><li><p>
<a class="indexterm" name="d0e20169"></a>
<code class="literal">access</code>: Dictionary for Microsoft Access. This is an alias
for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/AccessDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.AccessDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20184"></a>
<code class="literal">db2</code>: Dictionary for IBM's DB2 database. This is an alias for
the <a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/DB2Dictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.DB2Dictionary</code></a> class.
</p></li><li><p>
<a class="indexterm" name="d0e20199"></a>
<code class="literal">derby</code>: Dictionary for the Apache Derby database. This is an
alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/DerbyDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.DerbyDictionary</code> class.
</a>
</p></li><li><p>
<a class="indexterm" name="d0e20215"></a>
<code class="literal">empress</code>: Dictionary for Empress database This is an alias
for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/EmpressDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.EmpressDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20230"></a>
<code class="literal">foxpro</code>: Dictionary for Microsoft Visual FoxPro. This is an
alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/FoxProDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.FoxProDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20245"></a>
<code class="literal">hsql</code>: Dictionary for the Hypersonic SQL database. This is an
alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/HSQLDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.HSQLDictionary</code></a> class.
</p></li><li><p>
<a class="indexterm" name="d0e20260"></a>
<code class="literal">informix</code>: Dictionary for the Informix database. This is an
alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/InformixDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.InformixDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20275"></a>
<code class="literal">ingres</code>: Dictionary for Ingres. This is an alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/IngresDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.IngresDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20290"></a>
<code class="literal">jdatastore</code>: Dictionary for Borland JDataStore. This is an
alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/JDataStoreDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.JDataStoreDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20305"></a>
<code class="literal">mysql</code>: Dictionary for the MySQL database. This is an alias
for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/MySQLDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.MySQLDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20320"></a>
<code class="literal">oracle</code>: Dictionary for Oracle. This is an alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/OracleDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.OracleDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20335"></a>
<code class="literal">pointbase</code>: Dictionary for Pointbase Embedded database. This
is an alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/PointbaseDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.PointbaseDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20350"></a>
<code class="literal">postgres</code>: Dictionary for PostgreSQL. This is an alias for
the <a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/PostgresDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.PostgresDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20365"></a>
<code class="literal">sqlserver</code>: Dictionary for Microsoft's SQL Server database.
This is an alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/SQLServerDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.SQLServerDictionary</code></a>
class.
</p></li><li><p>
<a class="indexterm" name="d0e20380"></a>
<code class="literal">sybase</code>: Dictionary for Sybase. This is an alias for the
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="../javadoc/org/apache/openjpa/jdbc/sql/SybaseDictionary.html" target="_top">
<code class="classname">org.apache.openjpa.jdbc.sql.SybaseDictionary</code></a>
class.
</p></li></ul></div><p>
The example below demonstrates how to set a dictionary and configure its
properties in your configuration file. The <code class="literal">DBDictionary</code>
property uses OpenJPA's <a href="ref_guide_conf_plugins.html" title="4.&nbsp; Plugin Configuration">plugin syntax
</a>.
</p><div class="example"><a name="ref_guide_dbsetup_dbdict"></a><p class="title"><b>Example&nbsp;4.6.&nbsp;
Specifying a DBDictionary
</b></p><div class="example-contents"><pre class="programlisting">
&lt;property name="openjpa.jdbc.DBDictionary" value="hsql(SimulateLocking=true)"/&gt;
</pre></div></div><br class="example-break"><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="ref_guide_dbsetup_dbdictprops"></a>4.1.&nbsp;
DBDictionary Properties
</h3></div></div></div><p>
The standard dictionaries all recognize the following properties. These
properties will usually not need to be overridden, since the dictionary
implementation should use the appropriate default values for your database. You
typically won't use these properties unless you are designing your own
<code class="classname">DBDictionary</code> for an unsupported database.
</p><div class="itemizedlist"><ul type="disc"><li><p><a name="DBDictionary.AllowsAliasInBulkClause"></a>
<a class="indexterm" name="d0e20418"></a>
<code class="literal">AllowsAliasInBulkClause</code>:
When true, SQL delete and update statements may use table aliases.
</p></li><li><p><a name="DBDictionary.ArrayTypeName"></a>
<a class="indexterm" name="d0e20430"></a>
<code class="literal">ArrayTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.ARRAY</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.AutoAssignClause"></a>
<a class="indexterm" name="d0e20448"></a>
<code class="literal">AutoAssignClause</code>: The column definition clause to append to
a creation statement. For example, <code class="literal">"AUTO_INCREMENT"</code> for
MySQL. This property is set automatically in the dictionary, and should not need
to be overridden, and is only used when the schema is generated using the
<code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.AutoAssignTypeName"></a>
<a class="indexterm" name="d0e20468"></a>
<a class="indexterm" name="d0e20474"></a>
<code class="literal">AutoAssignTypeName</code>:
The column type name for auto-increment
columns. For example, <code class="literal">"BIGSERIAL"</code> for PostgreSQL. This
property is set automatically in the dictionary and should not need to be
overridden. It is used only when the schema is generated using the
<code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.BatchLimit"></a>
<a class="indexterm" name="d0e20494"></a>
<code class="literal">BatchLimit</code>:
The default batch limit for sending multiple SQL statements at once to the
database. A value of -1 indicates unlimited batching, and any positive integer
indicates the maximum number of SQL statements to batch together.
Defaults to 0 which disables batching.
</p></li><li><p><a name="DBDictionary.BigintTypeName"></a>
<a class="indexterm" name="d0e20506"></a>
<code class="literal">BigintTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.BIGINT</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.BinaryTypeName"></a>
<a class="indexterm" name="d0e20524"></a>
<code class="literal">BinaryTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.BINARY</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.BitTypeName"></a>
<a class="indexterm" name="d0e20542"></a>
<code class="literal">BitTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.BIT</code>. This is used only when the schema is generated by
the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.BlobBufferSize"></a>
<a class="indexterm" name="d0e20560"></a>
<code class="literal">BlobBufferSize</code>: This property establishes the buffer size in
the <code class="literal">INSERT/UPDATE</code> operations with an
<code class="literal">java.io.InputStream</code>. This is only used with OpenJPA's
<a href="ref_guide_mapping_jpa.html#ref_guide_streamsupport" title="7.11.&nbsp; LOB Streaming">Section&nbsp;7.11, &#8220;
LOB Streaming
&#8221;</a>. Defaults to 50000.
</p></li><li><p><a name="DBDictionary.BlobTypeName"></a>
<a class="indexterm" name="d0e20580"></a>
<a class="indexterm" name="d0e20586"></a>
<code class="literal">BlobTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.BLOB</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.BooleanTypeName"></a>
<a class="indexterm" name="d0e20604"></a>
<code class="literal">BooleanTypeName</code>:
The overridden default column type for
<code class="literal">java.sql.Types.BOOLEAN</code>. This is used only when the schema
is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.CastFunction"></a>
<a class="indexterm" name="d0e20622"></a>
<code class="literal">CastFunction</code>:
The SQL function call to cast a value to another SQL type.
Use the tokens <code class="literal">{0}</code> and <code class="literal">{1}</code> to represent
the two arguments. The result of the function is convert the
<code class="literal">{0}</code> value to a <code class="literal">{1}</code> type.
The default is <code class="literal">"CAST({0} AS {1})"</code>.
</p></li><li><p><a name="DBDictionary.CatalogSeparator"></a>
<a class="indexterm" name="d0e20649"></a>
<code class="literal">CatalogSeparator</code>: The string the database uses to delimit
between the schema name and the table name. This is typically <code class="literal">"."
</code>, which is the default.
</p></li><li><p><a name="DBDictionary.CharTypeName"></a>
<a class="indexterm" name="d0e20664"></a>
<code class="literal">CharTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.CHAR</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.CharacterColumnSize"></a>
<a class="indexterm" name="d0e20682"></a>
<code class="literal">CharacterColumnSize</code>: The default size of <code class="literal">varchar
</code> and <code class="literal">char</code> columns. Typically 255.
</p></li><li><p><a name="DBDictionary.ClobBufferSize"></a>
<a class="indexterm" name="d0e20700"></a>
<code class="literal">ClobBufferSize</code>: This property establish the buffer size in
the <code class="literal">INSERT/UPDATE</code> operations with a
<code class="literal">java.io.Reader</code>. This is only used with OpenJPA's
<a href="ref_guide_mapping_jpa.html#ref_guide_streamsupport" title="7.11.&nbsp; LOB Streaming">Section&nbsp;7.11, &#8220;
LOB Streaming
&#8221;</a>. Defaults to 50000.
</p></li><li><p><a name="DBDictionary.ClobTypeName"></a>
<a class="indexterm" name="d0e20720"></a>
<a class="indexterm" name="d0e20726"></a>
<code class="literal">ClobTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.CLOB</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.ClosePoolSQL"></a>
<a class="indexterm" name="d0e20744"></a>
<code class="literal">ClosePoolSQL</code>:
A special command to issue to the database when shutting down the pool.
Usually the pool of connections to the database is closed when the
application is ending. For embedded databases, whose lifecycle is
coterminous with the application, there may be a special
command, usually <code class="literal">"SHUTDOWN"</code>,
that will cause the embedded database to close cleanly.
Defaults to <code class="literal">null</code>.
</p></li><li><p><a name="DBDictionary.ConcatenateFunction"></a>
<a class="indexterm" name="d0e20762"></a>
<code class="literal">ConcatenateFunction</code>:
The SQL function call or operation to concatenate two strings.
Use the tokens <code class="literal">{0}</code> and <code class="literal">{1}</code> to represent
the two arguments. The result of the function or operation is to concatenate
the <code class="literal">{1}</code> string to the end of the <code class="literal">{0}</code>
string. Defaults to <code class="literal">"({0}||{1})"</code>.
</p></li><li><p><a name="DBDictionary.ConstraintNameMode"></a>
<a class="indexterm" name="d0e20789"></a>
<code class="literal">ConstraintNameMode</code>: When creating constraints, whether to
put the constraint name before the definition (<code class="literal">"before"</code>),
just after the constraint type name (<code class="literal">"mid"</code>), or after the
constraint definition (<code class="literal">"after"</code>).
Defaults to <code class="literal">"before"</code>.
</p></li><li><p><a name="DBDictionary.CreatePrimaryKeys"></a>
<a class="indexterm" name="d0e20813"></a>
<code class="literal">CreatePrimaryKeys</code>: When false, do not
create database primary keys for identifiers. Defaults to <code class="literal">true
</code>.
</p></li><li><p><a name="DBDictionary.CrossJoinClause"></a>
<a class="indexterm" name="d0e20828"></a>
<code class="literal">CrossJoinClause</code>: The clause to use for a cross join
(cartesian product). Defaults to <code class="literal">"CROSS JOIN"</code>.
</p></li><li><p><a name="DBDictionary.CurrentDateFunction"></a>
<a class="indexterm" name="d0e20843"></a>
<code class="literal">CurrentDateFunction</code>:
The SQL function call to obtain the current date from the database.
Defaults to <code class="literal">"CURRENT_DATE"</code>.
</p></li><li><p><a name="DBDictionary.CurrentTimeFunction"></a>
<a class="indexterm" name="d0e20858"></a>
<code class="literal">CurrentTimeFunction</code>:
The SQL function call to obtain the current time from the database.
Defaults to <code class="literal">"CURRENT_TIME"</code>.
</p></li><li><p><a name="DBDictionary.CurrentTimestampFunction"></a>
<a class="indexterm" name="d0e20873"></a>
<code class="literal">CurrentTimestampFunction</code>:
The SQL function call to obtain the current timestamp from the database.
Defaults to <code class="literal">"CURRENT_TIMESTAMP"</code>.
</p></li><li><p><a name="DBDictionary.DatePrecision"></a>
<a class="indexterm" name="d0e20888"></a>
<code class="literal">DatePrecision</code>:
The database is able to store time values to this degree of precision,
which is expressed in nanoseconds.
This value is usually one million, meaning that the database is able
to store time values with a precision of one millisecond. Particular
databases may have more or less precision.
OpenJPA will round all time values to this degree of precision
before storing them in the database.
Defaults to 1000000.
</p></li><li><p><a name="DBDictionary.DateTypeName"></a>
<a class="indexterm" name="d0e20900"></a>
<code class="literal">DateTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.DATE</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.DecimalTypeName"></a>
<a class="indexterm" name="d0e20918"></a>
<code class="literal">DecimalTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.DECIMAL</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.DelimitedCase"></a>
<a class="indexterm" name="d0e20936"></a>
<code class="literal">DelimitedCase</code>: The case to use when querying the database
about identifiers that have been delimited. It defaults to preserving the
case of the originally specified name. Available values are:
<code class="literal">upper, lower, preserve.</code>
</p></li><li><p><a name="DBDictionary.DistinctCountColumnSeparator"></a>
<a class="indexterm" name="d0e20951"></a>
<code class="literal">DistinctCountColumnSeparator</code>: The string the database uses
to delimit between column expressions in a <code class="literal">SELECT COUNT(DISTINCT
column-list)</code> clause. Defaults to <code class="literal">null</code>
for most databases, meaning that
multiple columns in a distinct COUNT clause are not supported.
</p></li><li><p><a name="DBDictionary.DistinctTypeName"></a>
<a class="indexterm" name="d0e20969"></a>
<code class="literal">DistinctTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.DISTINCT</code>. This is used only when the schema
is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.DoubleTypeName"></a>
<a class="indexterm" name="d0e20987"></a>
<code class="literal">DoubleTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.DOUBLE</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.DriverVendor"></a>
<a class="indexterm" name="d0e21005"></a>
<code class="literal">DriverVendor</code>: The vendor of the particular JDBC driver you
are using. Some dictionaries must alter their behavior depending on the driver
vendor. Dictionaries usually detect the driver vendor and set this property
themselves. See the <code class="literal">VENDOR_XXX</code> constants defined in the
<code class="classname">DBDictionary</code> Javadoc for available options.
</p></li><li><p><a name="DBDictionary.DropTableSQL"></a>
<a class="indexterm" name="d0e21023"></a>
<code class="literal">DropTableSQL</code>:
The SQL statement used to drop a table. Use the token <code class="literal">{0}</code>
as the argument for the table name.
Defaults to <code class="literal">"DROP TABLE {0}"</code>.
</p></li><li><p><a name="DBDictionary.FixedSizeTypeNames"></a>
<a class="indexterm" name="d0e21041"></a>
<code class="literal">FixedSizeTypeNames</code>:
A comma separated list of additional database types that have a size
defined by the database. In other words, when a column of a fixed
size type is declared, its size cannot be defined by the user. Common
examples would be <code class="literal">DATE</code>, <code class="literal">FLOAT</code>,
and <code class="literal">INTEGER</code>.
Each database dictionary has its own internal set of fixed size type names
that include the names mentioned here and many others.
Names added to this property are added to the dictionary's internal set.
Defaults to <code class="literal">null</code>.
</p></li><li><p><a name="DBDictionary.FloatTypeName"></a>
<a class="indexterm" name="d0e21065"></a>
<code class="literal">FloatTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.FLOAT</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.ForUpdateClause"></a>
<a class="indexterm" name="d0e21083"></a>
<a class="indexterm" name="d0e21089"></a>
<code class="literal">ForUpdateClause</code>: The clause to append to <code class="literal">SELECT
</code> statements to issue queries that obtain pessimistic locks. Defaults
to <code class="literal">"FOR UPDATE"</code>.
</p></li><li><p><a name="DBDictionary.GetStringVal"></a>
<a class="indexterm" name="d0e21107"></a>
<a class="indexterm" name="d0e21113"></a>
<code class="literal">GetStringVal</code>:
A special function to return the value of an XML
column in a select statement. For example, Oracle uses
<code class="literal">".getStringVal()"</code>, as in,
<code class="literal">"select t0.xmlcol.getStringVal() from xmltab t0"</code>.
Defaults to the empty string.
</p></li><li><p><a name="DBDictionary.InClauseLimit"></a>
<a class="indexterm" name="d0e21131"></a>
<a class="indexterm" name="d0e21137"></a>
<code class="literal">InClauseLimit</code>:
The maximum number of elements in an <code class="literal">IN</code> clause. OpenJPA
works around cases where the limit is exceeded. Defaults to -1 meaning
no limit.
</p></li><li><p><a name="DBDictionary.InitializationSQL"></a>
<a class="indexterm" name="d0e21152"></a>
<a class="indexterm" name="d0e21158"></a>
<code class="literal">InitializationSQL</code>: A piece of SQL to issue against the
database whenever a connection is retrieved from the <code class="classname">DataSource
</code>.
</p></li><li><p><a name="DBDictionary.InnerJoinClause"></a>
<a class="indexterm" name="d0e21173"></a>
<code class="literal">InnerJoinClause</code>: The clause to use for an inner join.
Defaults to <code class="literal">"INNER JOIN"</code>.
</p></li><li><p><a name="DBDictionary.IntegerTypeName"></a>
<a class="indexterm" name="d0e21188"></a>
<code class="literal">IntegerTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.INTEGER</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.JavaObjectTypeName"></a>
<a class="indexterm" name="d0e21206"></a>
<code class="literal">JavaObjectTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.JAVAOBJECT</code>. This is used only when the schema
is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.JoinSyntax"></a>
<a class="indexterm" name="d0e21224"></a>
<code class="literal">JoinSyntax</code>: The SQL join syntax to use in select statements.
See <a href="ref_guide_dbsetup_sql92.html" title="6.&nbsp; Setting the SQL Join Syntax">Section&nbsp;6, &#8220;
Setting the SQL Join Syntax
&#8221;</a>.
</p></li><li><p><a name="DBDictionary.LastGeneratedKeyQuery"></a>
<a class="indexterm" name="d0e21238"></a>
<code class="literal">LastGeneratedKeyQuery</code>: The query to issue to obtain the last
automatically generated key for an auto-increment column. For example,
<code class="literal">"SELECT LAST_INSERT_ID()"</code> for MySQL. This property is set
automatically in the dictionary, and should not need to be overridden.
If <code class="literal">SupportsGetGeneratedKeys</code> is true, the query will not
be issued but a more efficient JDBC 3.0 mechanism for obtaining generated
keys will be used instead.
</p></li><li><p><a name="DBDicationary.LeadingDelimiter"></a>
<a class="indexterm" name="d0e21258"></a>
<code class="literal">LeadingDelimiter</code>: The characters to use as the leading delimiter
for a delimited identifier. The default value is a double quote,
<code class="literal">(")</code>. See
<a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbsupport_delim_id" title="4.6.&nbsp; Delimited Identifiers Support">Section&nbsp;4.6, &#8220;
Delimited Identifiers Support
&#8221;</a> for
the default value for some specific databases.
</p></li><li><p><a name="DBDictionary.LongVarbinaryTypeName"></a>
<a class="indexterm" name="d0e21275"></a>
<code class="literal">LongVarbinaryTypeName</code>: The overridden default column type
for <code class="literal">java.sql.Types.LONGVARBINARY</code>. This is used only when the
schema is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.LongVarcharTypeName"></a>
<a class="indexterm" name="d0e21293"></a>
<code class="literal">LongVarcharTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.LONGVARCHAR</code>. This is used only when the
schema is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.MaxAutoAssignNameLength"></a>
<a class="indexterm" name="d0e21311"></a>
<code class="literal">MaxAutoAssignNameLength</code>: Set this property to the maximum
length of the sequence name used for auto-increment columns. Names longer than
this value are truncated. Defaults to 31.
</p></li><li><p><a name="DBDictionary.MaxColumnNameLength"></a>
<a class="indexterm" name="d0e21323"></a>
<code class="literal">MaxColumnNameLength</code>: The maximum number of characters in a
column name. Defaults to 128.
</p></li><li><p><a name="DBDictionary.MaxConstraintNameLength"></a>
<a class="indexterm" name="d0e21335"></a>
<code class="literal">MaxConstraintNameLength</code>: The maximum number of characters in
a constraint name. Defaults to 128.
</p></li><li><p><a name="DBDictionary.MaxEmbeddedBlobSize"></a>
<a class="indexterm" name="d0e21347"></a>
<code class="literal">MaxEmbeddedBlobSize</code>:
When greater than -1, the maximum size of a <code class="literal">BLOB</code> value
that can be sent directly to the database within an insert or update statement.
Values whose size is greater than <code class="literal">MaxEmbeddedBlobSize</code> force
OpenJPA to work around this limitation. A value of -1 means that there is
no limitation. Defaults to -1.
</p></li><li><p><a name="DBDictionary.MaxEmbeddedClobSize"></a>
<a class="indexterm" name="d0e21365"></a>
<code class="literal">MaxEmbeddedClobSize</code>:
When greater than -1, the maximum size of a <code class="literal">CLOB</code> value
that can be sent directly to the database within an insert or update statement.
Values whose size is greater than <code class="literal">MaxEmbeddedClobSize</code> force
OpenJPA to work around this limitation. A value of -1 means that there is
no limitation. Defaults to -1.
</p></li><li><p><a name="DBDictionary.MaxIndexNameLength"></a>
<a class="indexterm" name="d0e21383"></a>
<a class="indexterm" name="d0e21389"></a>
<code class="literal">MaxIndexNameLength</code>: The maximum number of characters in an
index name. Defaults to 128.
</p></li><li><p><a name="DBDictionary.MaxIndexesPerTable"></a>
<a class="indexterm" name="d0e21401"></a>
<code class="literal">MaxIndexesPerTable</code>: The maximum number of indexes that can
be placed on a single table. Defaults to no limit.
</p></li><li><p><a name="DBDictionary.MaxTableNameLength"></a>
<a class="indexterm" name="d0e21413"></a>
<code class="literal">MaxTableNameLength</code>: The maximum number of characters in a
table name. Defaults to 128.
</p></li><li><p><a name="DBDictionary.NameConcatenator"></a>
<a class="indexterm" name="d0e21425"></a>
<code class="literal">NameConcatenator</code>: The value used when names are concatenated to
create a generated name. The default value is the underscore <code class="literal">"_"</code>.
</p></li><li><p><a name="DBDictionary.NextSequenceQuery"></a>
<a class="indexterm" name="d0e21440"></a>
<code class="literal">NextSequenceQuery</code>: A SQL string for obtaining a native
sequence value. May use a placeholder of <code class="literal">{0}</code> for the variable
sequence name. Defaults to a database-appropriate value. For example,
<code class="literal">"SELECT {0}.NEXTVAL FROM DUAL"</code> for Oracle.
</p></li><li><p><a name="DBDictionary.NullTypeName"></a>
<a class="indexterm" name="d0e21458"></a>
<code class="literal">NullTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.NULL</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.NumericTypeName"></a>
<a class="indexterm" name="d0e21476"></a>
<code class="literal">NumericTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.NUMERIC</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.OtherTypeName"></a>
<a class="indexterm" name="d0e21494"></a>
<code class="literal">OtherTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.OTHER</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.OuterJoinClause"></a>
<a class="indexterm" name="d0e21512"></a>
<code class="literal">OuterJoinClause</code>: The clause to use for an left outer join.
Defaults to <code class="literal">"LEFT OUTER JOIN"</code>.
</p></li><li><p><a name="DBDictionary.Platform"></a>
<a class="indexterm" name="d0e21527"></a>
<code class="literal">Platform</code>:
The name of the database that this dictionary targets.
Defaults to <code class="literal">"Generic"</code>, but all dictionaries override this
value.
</p></li><li><p><a name="DBDictionary.RangePosition"></a>
<a class="indexterm" name="d0e21542"></a>
<code class="literal">RangePosition</code>:
Indicates where to specify in the SQL select statement the range, if any,
of the result rows to be returned.
When limiting the number of returned result rows to a subset of all those
that satisfy the query's conditions, the position of the range clause
varies by database.
Defaults to 0, meaning that the range
is expressed at the end of the select statement but before any locking clause.
See the RANGE_XXX constants defined in <code class="classname">DBDictionary</code>.
</p></li><li><p><a name="DBDictionary.RealTypeName"></a>
<a class="indexterm" name="d0e21557"></a>
<code class="literal">RealTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.REAL</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.RefTypeName"></a>
<a class="indexterm" name="d0e21575"></a>
<code class="literal">RefTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.REF</code>. This is used only when the schema is generated by
the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.RequiresAliasForSubselect"></a>
<a class="indexterm" name="d0e21593"></a>
<a class="indexterm" name="d0e21599"></a>
<code class="literal">RequiresAliasForSubselect</code>: When true, the database
requires that subselects in a FROM clause be assigned an alias.
</p></li><li><p><a name="DBDictionary.RequiresAutoCommitForMetadata"></a>
<a class="indexterm" name="d0e21613"></a>
<code class="literal">RequiresAutoCommitForMetadata</code>: When true, the JDBC driver
requires that autocommit be enabled before any schema interrogation operations
can take place.
</p></li><li><p><a name="DBDictionary.RequiresCastForComparisons"></a>
<a class="indexterm" name="d0e21627"></a>
<code class="literal">RequiresCastForComparisons</code>:
When true, comparisons of two values of different types or
of two literals requires a cast in the generated SQL.
Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.RequiresCastForMathFunctions"></a>
<a class="indexterm" name="d0e21642"></a>
<code class="literal">RequiresCastForMathFunctions</code>:
When true, math operations on two values of different types or
on two literals requires a cast in the generated SQL.
Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.RequiresConditionForCrossJoin"></a>
<a class="indexterm" name="d0e21657"></a>
<code class="literal">RequiresConditionForCrossJoin</code>: Some databases require that
there always be a conditional statement for a cross join. If set, this parameter
ensures that there will always be some condition to the join clause.
</p></li><li><p><a name="DBDictionary.RequiresTargetForDelete"></a>
<a class="indexterm" name="d0e21669"></a>
<code class="literal">RequiresTargetForDelete</code>:
When true, the database requires a target for delete statements. Defaults
to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.ReservedWords"></a>
<a class="indexterm" name="d0e21684"></a>
<code class="literal">ReservedWords</code>: A comma-separated list of reserved words for
this database, beyond the standard SQL92 keywords.
</p></li><li><p><a name="DBDictionary.SchemaCase"></a>
<a class="indexterm" name="d0e21696"></a>
<code class="literal">SchemaCase</code>: The case to use when querying the database
metadata about schema components. Defaults to making all names upper case.
Available values are: <code class="literal">upper, lower, preserve</code>.
</p></li><li><p><a name="DBDictionary.SearchStringEscape"></a>
<a class="indexterm" name="d0e21713"></a>
<code class="literal">SearchStringEscape</code>:
The default escape character used when generating SQL <code class="literal">LIKE</code>
clauses. The escape character is used to escape the wildcard meaning of the
<code class="literal">_</code> and <code class="literal">%</code> characters.
Note: since JPQL provides the ability to define the escape character in
the query, this setting is primarily used when translating other query
languages, such as JDOQL. Defaults to <code class="literal">"\\"</code>
(a single backslash in Java speak).
</p></li><li><p><a name="DBDictionary.RequiresSearchStringEscapeForLike"></a>
<a class="indexterm" name="d0e21737"></a>
<code class="literal">RequiresSearchStringEscapeForLike</code>:
When true, the database requires an escape string for queries that use
<code class="literal">LIKE</code>. The escape string can be specified using
<code class="literal">searchStringEscape</code>. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SelectWords"></a>
<a class="indexterm" name="d0e21758"></a>
<code class="literal">SelectWords</code>: A comma-separated list of keywords which may be
used to start a SELECT statement for this database. If an application executes
a native SQL statement which begins with SelectWords OpenJPA will treat the
statement as a SELECT statement rather than an UPDATE statement.
</p></li><li><p><a name="DBDictionary.SequenceNameSQL"></a>
<a class="indexterm" name="d0e21770"></a>
<code class="literal">SequenceNameSQL</code>:
Additional phrasing to use with <code class="literal">SequenceSQL</code>.
Defaults to <code class="literal">null</code>.
</p></li><li><p><a name="DBDictionary.SequenceSQL"></a>
<a class="indexterm" name="d0e21790"></a>
<code class="literal">SequenceSQL</code>:
General structure of the SQL query to use when interrogating the database
for sequence names.
As there is no standard way to obtain sequence names,
it defaults to <code class="literal">null</code>.
</p></li><li><p><a name="DBDictionary.SequenceSchemaSQL"></a>
<a class="indexterm" name="d0e21807"></a>
<code class="literal">SequenceSchemaSQL</code>:
Additional phrasing to use with <code class="literal">SequenceSQL</code>.
Defaults to <code class="literal">null</code>.
</p></li><li><p><a name="DBDictionary.SimulateLocking"></a>
<a class="indexterm" name="d0e21827"></a>
<code class="literal">SimulateLocking</code>: Some databases do not support pessimistic
locking, which will result in an exception when you attempt a
transaction while using the pessimistic lock manager.
Setting this property to <code class="literal">true</code> suppresses the
locking of rows in the database, thereby allowing pessimistic transactions
even on databases that do not support locking. At the same time, setting this
property to <code class="literal">true</code> means that you do not obtain the semantics
of a pessimistic
transaction with the database. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SmallintTypeName"></a>
<a class="indexterm" name="d0e21848"></a>
<code class="literal">SmallintTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.SMALLINT</code>. This is used only when the schema
is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.StorageLimitationsFatal"></a>
<a class="indexterm" name="d0e21866"></a>
<code class="literal">StorageLimitationsFatal</code>: When true, any data
truncation/rounding that is performed by the dictionary in order to store a
value in the database will be treated as a fatal error, rather than just issuing
a warning.
</p></li><li><p><a name="DBDictionary.StoreCharsAsNumbers"></a>
<a class="indexterm" name="d0e21878"></a>
<code class="literal">StoreCharsAsNumbers</code>: Set this property to <code class="literal">false
</code> to store Java <code class="literal">char</code> fields as <code class="literal">CHAR
</code> values rather than numbers. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.StoreLargeNumbersAsStrings"></a>
<a class="indexterm" name="d0e21902"></a>
<code class="literal">StoreLargeNumbersAsStrings</code>: When true, the dictionary
prefers to store Java fields of
type <code class="classname">BigInteger</code> and <code class="classname">BigDecimal</code>
as string values in the database. Likewise, the dictionary will instruct
the mapping tool to map these Java types to character columns.
Because some databases have limitations on the number of digits that can
be stored in a numeric column (for example, Oracle can only store 38
digits), this option may be necessary for some applications.
Note that this option may prevent OpenJPA from executing meaningful numeric
queries against the columns. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.StringLengthFunction"></a>
<a class="indexterm" name="d0e21923"></a>
<code class="literal">StringLengthFunction</code>: Name of the SQL function for getting
the length of a string. Use the token <code class="literal">{0}</code> to represent the
argument.
</p></li><li><p><a name="DBDictionary.StructTypeName"></a>
<a class="indexterm" name="d0e21938"></a>
<code class="literal">StructTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.STRUCT</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.SubstringFunctionName"></a>
<a class="indexterm" name="d0e21956"></a>
<code class="literal">SubstringFunctionName</code>: Name of the SQL function for getting
the substring of a string.
</p></li><li><p><a name="DBDictionary.SupportsAlterTableWithAddColumn"></a>
<a class="indexterm" name="d0e21968"></a>
<code class="literal">SupportsAlterTableWithAddColumn</code>: When true, the database
supports adding a new column in an ALTER TABLE statement.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsAlterTableWithDropColumn"></a>
<a class="indexterm" name="d0e21983"></a>
<code class="literal">SupportsAlterTableWithDropColumn</code>: When true, the database
supports dropping a column in an ALTER TABLE statement.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsAutoAssign"></a>
<a class="indexterm" name="d0e21998"></a>
<code class="literal">SupportsAutoAssign</code>:
When true, the database supports auto-assign columns, where the value of
column is assigned upon insertion of the row into the database.
Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SupportsCascadeDeleteAction"></a>
<a class="indexterm" name="d0e22013"></a>
<code class="literal">SupportsCascadeDeleteAction</code>: When true, the database supports
the <code class="literal">CASCADE</code> delete action on foreign keys.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsCascadeUpdateAction"></a>
<a class="indexterm" name="d0e22031"></a>
<code class="literal">SupportsCascadeUpdateAction</code>:
When true, the database supports the <code class="literal">CASCADE</code>
update action on foreign keys. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsComments"></a>
<a class="indexterm" name="d0e22049"></a>
<code class="literal">SupportsComments</code>:
When true, comments can be associated with the table in the table creation
statement. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SupportsCorrelatedSubselect"></a>
<a class="indexterm" name="d0e22064"></a>
<code class="literal">SupportsCorrelatedSubselect</code>:
When true, the database supports correlated subselects. Correlated
subselects are select statements nested within select statements that
refers to a column in the outer select statement. For performance
reasons, correlated subselects are generally a last resort.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsDefaultDeleteAction"></a>
<a class="indexterm" name="d0e22079"></a>
<code class="literal">SupportsDefaultDeleteAction</code>: When true, the database supports
the <code class="literal">SET DEFAULT</code> delete action on foreign keys.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsDefaultUpdateAction"></a>
<a class="indexterm" name="d0e22097"></a>
<code class="literal">SupportsDefaultUpdateAction</code>:
When true, the database supports the <code class="literal">SET DEFAULT</code> update
action on foreign keys. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsDeferredConstraints"></a>
<a class="indexterm" name="d0e22115"></a>
<code class="literal">SupportsDeferredConstraints</code>: When true, the database
supports deferred constraints. The
database supports deferred constraints by checking for constraint
violations when the transaction commits, rather than checking for
violations immediately after receiving each SQL statement within the
transaction. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsDelimitedIdentifiers"></a>
<a class="indexterm" name="d0e22130"></a>
<code class="literal">SupportsDelimitedIdentifiers</code>: When true, the database
supports delimited identifiers. It defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsForeignKeys"></a>
<a class="indexterm" name="d0e22145"></a>
<code class="literal">SupportsForeignKeys</code>: When true, the database supports foreign
keys. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsForeignKeysComposite"></a>
<a class="indexterm" name="d0e22160"></a>
<code class="literal">SupportsForeignKeysComposite</code>: When true, the database supports
composite foreign keys. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsGetGeneratedKeys"></a>
<a class="indexterm" name="d0e22175"></a>
<code class="literal">SupportsGetGeneratedKeys</code>: When true, OpenJPA will use
<code class="methodname">java.sql.Statement.getGeneratedKeys</code> method to obtain
values of auto-increment columns. When false, a query specified by
<code class="literal">LastGeneratedKeyQuery</code> will be used for that purpose.
If not set, the value will be auto-detected by querying the JDBC driver.
Setting the value to true requires that the JDBC
driver supports version 3.0 or higher of the JDBC specification
and supports the <code class="methodname">java.sql.Statement.getGeneratedKeys</code>
method.
</p></li><li><p><a name="DBDictionary.SupportsHaving"></a>
<a class="indexterm" name="d0e22198"></a>
<code class="literal">SupportsHaving</code>: When true, the database supports HAVING
clauses in selects.
</p></li><li><p><a name="DBDictionary.SupportsLockingWithDistinctClause"></a>
<a class="indexterm" name="d0e22212"></a>
<code class="literal">SupportsLockingWithDistinctClause</code>: When true, the
database supports <code class="literal">FOR UPDATE</code> select clauses with
<code class="literal">DISTINCT</code> clauses.
</p></li><li><p><a name="DBDictionary.SupportsLockingWithInnerJoin"></a>
<a class="indexterm" name="d0e22230"></a>
<code class="literal">SupportsLockingWithInnerJoin</code>: When true, the database
supports <code class="literal">FOR UPDATE</code> select clauses with inner join queries.
</p></li><li><p><a name="DBDictionary.SupportsLockingWithMultipleTables"></a>
<a class="indexterm" name="d0e22245"></a>
<code class="literal">SupportsLockingWithMultipleTables</code>: When true, the
database supports <code class="literal">FOR UPDATE</code> select clauses that select from
multiple tables.
</p></li><li><p><a name="DBDictionary.SupportsLockingWithOrderClause"></a>
<a class="indexterm" name="d0e22260"></a>
<code class="literal">SupportsLockingWithOrderClause</code>: When true, the database
supports <code class="literal">FOR UPDATE</code> select clauses with <code class="literal">ORDER BY
</code> clauses.
</p></li><li><p><a name="DBDictionary.SupportsLockingWithOuterJoin"></a>
<a class="indexterm" name="d0e22278"></a>
<code class="literal">SupportsLockingWithOuterJoin</code>: When true, the database
supports <code class="literal">FOR UPDATE</code> select clauses with outer join queries.
</p></li><li><p><a name="DBDictionary.SupportsLockingWithSelectRange"></a>
<a class="indexterm" name="d0e22293"></a>
<code class="literal">SupportsLockingWithSelectRange</code>: When true, the database
supports <code class="literal">FOR UPDATE</code> select clauses with queries that select a
range of data using <code class="literal">LIMIT</code>, <code class="literal">TOP</code> or the
database equivalent. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsModOperator"></a>
<a class="indexterm" name="d0e22317"></a>
<code class="literal">SupportsModOperator</code>:
When true, the database supports the modulus operator (<code class="literal">%</code>)
instead of the <code class="literal">MOD</code> function.
Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SupportsMultipleNontransactionalResultSets"></a>
<code class="literal">SupportsMultipleNontransactionalResultSets</code>: When true, a
nontransactional connection is capable of having multiple open
<code class="classname">ResultSet</code> instances.
</p></li><li><p><a name="DBDictionary.SupportsNullDeleteAction"></a>
<a class="indexterm" name="d0e22347"></a>
<code class="literal">SupportsNullDeleteAction</code>: When true, the database supports
the <code class="literal">SET NULL</code> delete action on foreign keys.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsNullTableForGetColumns"></a>
<a class="indexterm" name="d0e22365"></a>
<code class="literal">SupportsNullTableForGetColumns</code>: When true, the database
supports passing a <code class="literal">null</code> parameter to <code class="methodname">
DatabaseMetaData.getColumns</code> as an optimization to get information
about all the tables. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsNullTableForGetImportedKeys"></a>
<a class="indexterm" name="d0e22388"></a>
<code class="literal">SupportsNullTableForGetImportedKeys</code>: When true, the
database supports passing a <code class="literal">null</code> parameter to <code class="methodname">
DatabaseMetaData.getImportedKeys</code> as an optimization to get
information about all the tables. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SupportsNullTableForGetIndexInfo"></a>
<a class="indexterm" name="d0e22411"></a>
<code class="literal">SupportsNullTableForGetIndexInfo</code>: When true, the database
supports passing a <code class="literal">null</code> parameter to <code class="methodname">
DatabaseMetaData.getIndexInfo</code> as an optimization to get information
about all the tables. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SupportsNullTableForGetPrimaryKeys"></a>
<a class="indexterm" name="d0e22434"></a>
<code class="literal">SupportsNullTableForGetPrimaryKeys</code>: When true, the
database supports passing a <code class="literal">null</code> parameter to <code class="methodname">
DatabaseMetaData.getPrimaryKeys</code> as an optimization to get
information about all the tables. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SupportsNullUpdateAction"></a>
<a class="indexterm" name="d0e22457"></a>
<code class="literal">SupportsNullUpdateAction</code>:
When true, the database supports the <code class="literal">SET NULL</code> update
action on foreign keys. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsQueryTimeout"></a>
<a class="indexterm" name="d0e22475"></a>
<code class="literal">SupportsQueryTimeout</code>: When true, the JDBC driver supports
calls to <code class="methodname"> java.sql.Statement.setQueryTimeout</code>.
</p></li><li><p><a name="DBDictionary.SupportsRestrictDeleteAction"></a>
<a class="indexterm" name="d0e22492"></a>
<code class="literal">SupportsRestrictDeleteAction</code>: When true, the database
supports the <code class="literal">RESTRICT</code> delete action on foreign keys.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsRestrictUpdateAction"></a>
<a class="indexterm" name="d0e22510"></a>
<code class="literal">SupportsRestrictUpdateAction</code>:
When true, the database supports the <code class="literal">RESTRICT</code> update
action on foreign keys. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsSchemaForGetColumns"></a>
<a class="indexterm" name="d0e22528"></a>
<code class="literal">SupportsSchemaForGetColumns</code>: When false, the database
driver does not support using the schema name for schema reflection on column
names.
</p></li><li><p><a name="DBDictionary.SupportsSchemaForGetTables"></a>
<a class="indexterm" name="d0e22542"></a>
<code class="literal">SupportsSchemaForGetTables</code>: If false, then the database
driver does not support using the schema name for schema reflection on table
names.
</p></li><li><p><a name="DBDictionary.SupportsSelectEndIndex"></a>
<a class="indexterm" name="d0e22556"></a>
<code class="literal">SupportsSelectEndIndex</code>: When true, the database can create a
select that is limited to the first N results.
</p></li><li><p><a name="DBDictionary.SupportsSelectForUpdate"></a>
<a class="indexterm" name="d0e22570"></a>
<code class="literal">SupportsSelectForUpdate</code>: When true, the database supports
<code class="literal">SELECT</code> statements with a pessimistic locking
(<code class="literal">FOR UPDATE</code>) clause. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsSelectStartIndex"></a>
<a class="indexterm" name="d0e22591"></a>
<code class="literal">SupportsSelectStartIndex</code>: When true, the database can create a
select that skips the first N results.
</p></li><li><p><a name="DBDictionary.SupportsSimpleCaseExpression"></a>
<a class="indexterm" name="d0e22605"></a>
<code class="literal">SupportsSimpleCaseExpression</code>: When true, the database supports
the simple form of <code class="literal">CASE</code> expression:
<code class="literal">CASE &lt;a&gt; WHEN &lt;b&gt; THEN &lt;c&gt; WHEN &lt;d&gt; THEN &lt;e&gt; ELSE &lt;f&gt; END</code>.
When false, the general form of <code class="literal">CASE</code> expression will be used:
<code class="literal">CASE WHEN &lt;a&gt; = &lt;b&gt; THEN &lt;c&gt; WHEN &lt;a&gt; = &lt;d&gt; THEN &lt;e&gt; ELSE &lt;f&gt; END</code>.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsSubselect"></a>
<a class="indexterm" name="d0e22632"></a>
<a class="indexterm" name="d0e22638"></a>
<code class="literal">SupportsSubselect</code>: When true, the database supports subselects
in queries.
</p></li><li><p><a name="DBDictionary.SupportsTimestampNanos"></a>
<a class="indexterm" name="d0e22652"></a>
<code class="literal">SupportsTimestampNanos</code>: When true, the database supports
nanoseconds with TIMESTAMP columns.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsUniqueConstraints"></a>
<a class="indexterm" name="d0e22665"></a>
<code class="literal">SupportsUniqueConstraints</code>: When true, the database supports
unique constraints. Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="DBDictionary.SupportsXMLColumn"></a>
<a class="indexterm" name="d0e22680"></a>
<code class="literal">SupportsXMLColumn</code>:
When true, the database supports an XML column type. See
<a href="ref_guide_mapping_jpa.html#ref_guide_xmlmapping" title="7.10.&nbsp; XML Column Mapping">Section&nbsp;7.10, &#8220;
XML Column Mapping
&#8221;</a>
for information on using this capability. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.SystemSchemas"></a>
<a class="indexterm" name="d0e22697"></a>
<code class="literal">SystemSchemas</code>: A comma-separated list of schema names that
should be ignored.
</p></li><li><p><a name="DBDictionary.SystemTables"></a>
<a class="indexterm" name="d0e22711"></a>
<code class="literal">SystemTables</code>: A comma-separated list of table names that
should be ignored.
</p></li><li><p><a name="DBDictionary.TableForUpdateClause"></a>
<a class="indexterm" name="d0e22725"></a>
<a class="indexterm" name="d0e22731"></a>
<code class="literal">TableForUpdateClause</code>: The clause to append to the end of
each table alias in queries that obtain pessimistic locks.
Defaults to <code class="literal">null</code>.
</p></li><li><p><a name="DBDictionary.TableTypes"></a>
<a class="indexterm" name="d0e22746"></a>
<code class="literal">TableTypes</code>: Comma-separated list of table types to use when
looking for tables during schema reflection, as defined in the <code class="methodname">
java.sql.DatabaseMetaData.getTableInfo</code> JDBC method. An example is:
<code class="literal">"TABLE,VIEW,ALIAS"</code>. Defaults to <code class="literal">"TABLE"</code>.
</p></li><li><p><a name="DBDictionary.TimeTypeName"></a>
<a class="indexterm" name="d0e22769"></a>
<code class="literal">TimeTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.TIME</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.TimestampTypeName"></a>
<a class="indexterm" name="d0e22787"></a>
<code class="literal">TimestampTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.TIMESTAMP</code>. This is used only when the schema
is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.TinyintTypeName"></a>
<a class="indexterm" name="d0e22805"></a>
<code class="literal">TinyintTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.TINYINT</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.ToLowerCaseFunction"></a>
<a class="indexterm" name="d0e22823"></a>
<code class="literal">ToLowerCaseFunction</code>: Name of the SQL function for converting
a string to lower case. Use the token <code class="literal">{0}</code> to represent the
argument.
</p></li><li><p><a name="DBDictionary.ToUpperCaseFunction"></a>
<a class="indexterm" name="d0e22838"></a>
<code class="literal">ToUpperCaseFunction</code>: SQL function call for converting a
string to upper case. Use the token <code class="literal">{0}</code> to represent the
argument.
</p></li><li><p><a name="DBDicationary.TrailingDelimiter"></a>
<a class="indexterm" name="d0e22853"></a>
<code class="literal">TrailingDelimiter</code>: The characters to use as the trailing delimiter
for a delimited identifier. The default value is a double quote,
<code class="literal">(")</code>. See
<a href="ref_guide_dbsetup_dbsupport.html#ref_guide_dbsetup_dbsupport_delim_id" title="4.6.&nbsp; Delimited Identifiers Support">Section&nbsp;4.6, &#8220;
Delimited Identifiers Support
&#8221;</a> for
the default value for some specific databases.
</p></li><li><p><a name="DBDictionary.TrimBothFunction"></a>
<a class="indexterm" name="d0e22870"></a>
<code class="literal">TrimBothFunction</code>:
The SQL function call to trim any number of a particular character
from both the start and end of a string.
Note: some databases do not support specifying the character in which
case only spaces or whitespace can be trimmed.
Use the token <code class="literal">{1}</code> when possible to represent the character,
and the token <code class="literal">{0}</code> to represent the string.
Defaults to <code class="literal">"TRIM(BOTH {1} FROM {0})"</code>.
</p></li><li><p><a name="DBDictionary.TrimLeadingFunction"></a>
<a class="indexterm" name="d0e22891"></a>
<code class="literal">TrimLeadingFunction</code>:
The SQL function call to trim any number of a particular character
from the start of a string.
Note: some databases do not support specifying the character in which
case only spaces or whitespace can be trimmed.
Use the token <code class="literal">{1}</code> when possible to represent the character,
and the token <code class="literal">{0}</code> to represent the string.
Defaults to <code class="literal">"TRIM(LEADING {1} FROM {0})"</code>.
</p></li><li><p><a name="DBDictionary.TrimTrailingFunction"></a>
<a class="indexterm" name="d0e22912"></a>
<code class="literal">TrimTrailingFunction</code>:
The SQL function call to trim any number of a particular character
from the end of a string.
Note: some databases do not support specifying the character in which
case only spaces or whitespace can be trimmed.
Use the token <code class="literal">{1}</code> when possible to represent the character,
and the token <code class="literal">{0}</code> to represent the string.
Defaults to <code class="literal">"TRIM(TRAILING {1} FROM {0})"</code>.
</p></li><li><p><a name="DBDictionary.UseGetBestRowIdentifierForPrimaryKeys"></a>
<a class="indexterm" name="d0e22933"></a>
<code class="literal">UseGetBestRowIdentifierForPrimaryKeys</code>: When true,
metadata queries will use <code class="methodname">DatabaseMetaData.getBestRowIdentifier
</code> to obtain information about primary keys, rather than <code class="methodname">
DatabaseMetaData.getPrimaryKeys</code>.
</p></li><li><p><a name="DBDictionary.UseGetBytesForBlobs"></a>
<a class="indexterm" name="d0e22953"></a>
<code class="literal">UseGetBytesForBlobs</code>: When true, <code class="methodname">
ResultSet.getBytes</code> will be used to obtain blob data rather than
<code class="methodname">ResultSet.getBinaryStream</code>.
</p></li><li><p><a name="DBDictionary.UseGetObjectForBlobs"></a>
<a class="indexterm" name="d0e22971"></a>
<code class="literal">UseGetObjectForBlobs</code>: When true, <code class="methodname">
ResultSet.getObject</code> will be used to obtain blob data rather than
<code class="methodname">ResultSet.getBinaryStream</code>.
</p></li><li><p><a name="DBDictionary.UseGetStringForClobs"></a>
<a class="indexterm" name="d0e22989"></a>
<code class="literal">UseGetStringForClobs</code>: When true, <code class="methodname">
ResultSet.getString</code> will be used to obtain clob data rather than
<code class="methodname">ResultSet.getCharacterStream</code>.
</p></li><li><p><a name="DBDictionary.UseSchemaName"></a>
<a class="indexterm" name="d0e23007"></a>
<code class="literal">UseSchemaName</code>: If <code class="literal">false</code>, then avoid
including the schema name in table name references. Defaults to <code class="literal">true
</code>.
</p></li><li><p><a name="DBDictionary.UseSetBytesForBlobs"></a>
<a class="indexterm" name="d0e23025"></a>
<code class="literal">UseSetBytesForBlobs</code>: When true, <code class="methodname">
PreparedStatement.setBytes</code> will be used to set blob data, rather
than <code class="methodname">PreparedStatement.setBinaryStream</code>.
</p></li><li><p><a name="DBDictionary.UseSetStringForClobs"></a>
<a class="indexterm" name="d0e23043"></a>
<code class="literal">UseSetStringForClobs</code>: When true, <code class="methodname">
PreparedStatement.setString</code> will be used to set clob data, rather
than <code class="methodname">PreparedStatement.setCharacterStream</code>.
</p></li><li><p><a name="DBDictionary.UseWildCardForCount"></a>
<a class="indexterm" name="d0e23061"></a>
<code class="literal">UseWildCardForCount</code>: When true, the JPQL <code class="literal">COUNT</code>
aggregate function will be translated into SQL <code class="literal">COUNT(*)</code> expression
if the SQL query does not involve joins. Defaults to <code class="literal">false</code>.
</p></li><li><p><a name="DBDictionary.ValidationSQL"></a>
<a class="indexterm" name="d0e23082"></a>
<a class="indexterm" name="d0e23088"></a>
<code class="literal">ValidationSQL</code>: The SQL used to validate that a connection is
still in a valid state. For example, <code class="literal">"SELECT SYSDATE FROM DUAL"
</code> for Oracle.
</p></li><li><p><a name="DBDictionary.VarbinaryTypeName"></a>
<a class="indexterm" name="d0e23103"></a>
<code class="literal">VarbinaryTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.VARBINARY</code>. This is used only when the schema
is generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.VarcharTypeName"></a>
<a class="indexterm" name="d0e23121"></a>
<code class="literal">VarcharTypeName</code>: The overridden default column type for
<code class="literal">java.sql.Types.VARCHAR</code>. This is used only when the schema is
generated by the <code class="literal">mappingtool</code>.
</p></li><li><p><a name="DBDictionary.XmlTypeName"></a>
<a class="indexterm" name="d0e23139"></a>
<code class="literal">XmlTypeName</code>:
The column type name for XML columns. This
property is set automatically in the dictionary and should not need to be
overridden. It is used only when the schema is generated using the
<code class="literal">mappingtool</code>. Defaults to <code class="literal">"XML"</code>.
</p></li></ul></div></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="ref_guide_dbsetup_dbsupport_firebird"></a>4.2.&nbsp;
FirebirdDictionary Properties
</h3></div></div></div><a class="indexterm" name="d0e23158"></a><p>
The <code class="literal">firebird</code> dictionary understands the following additional
properties:
</p><div class="itemizedlist"><ul type="disc"><li><p><a name="FirebirdDictionary.FirebirdVersion"></a>
<a class="indexterm" name="d0e23172"></a>
<code class="literal">FirebirdVersion</code>: The database version OpenJPA connects to.
This property affects the SQL statements executed by OpenJPA.
Available values are: 15, 20 and 21
- they indicate Firebird versions 1.5, 2.0 and 2.1 respectively.
If not set, the value will be auto-detected.
</p></li><li><p><a name="FirebirdDictionary.IndexedVarcharMaxSizeFB15"></a>
<a class="indexterm" name="d0e23184"></a>
<code class="literal">IndexedVarcharMaxSizeFB15</code>: Firebird 1.5 imposes
tight limits on index size. In particular, an indexed
<code class="literal">VARCHAR</code> column size cannot exceed 252.
When <a href="ref_guide_mapping.html#ref_guide_mapping_mappingtool" title="1.&nbsp; Forward Mapping">schema is created</a>,
OpenJPA will use this property to reduce the size
of indexed <code class="literal">VARCHAR</code> columns.
Defaults to 252 but you might want to decrease this value if multi-column
indexes are used. If the Firebird version is 2.0 or later or
schema creation is not used, this property does not matter.
</p></li><li><p><a name="FirebirdDictionary.RangeSyntax"></a>
<a class="indexterm" name="d0e23205"></a>
<code class="literal">RangeSyntax</code>: Firebird 2.0 and later support two
ways of handling queries that select a range of data:
<code class="literal">"FIRST &lt;p&gt; SKIP &lt;q&gt;"</code> and
<code class="literal">"ROWS &lt;m&gt; TO &lt;n&gt;"</code>. Earlier versions support only
<code class="literal">"FIRST &lt;p&gt; SKIP &lt;q&gt;"</code> syntax.
This property determines the syntax to be used.
Available values are:
<code class="literal">"firstskip"</code> and <code class="literal">"rows"</code>.
Defaults to using <code class="literal">"ROWS &lt;m&gt; TO &lt;n&gt;"</code> if the
Firebird version is 2.0 or later, and
<code class="literal">"FIRST &lt;p&gt; SKIP &lt;q&gt;"</code> otherwise.
</p></li></ul></div></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="ref_guide_dbsetup_dbsupport_mysql"></a>4.3.&nbsp;
MySQLDictionary Properties
</h3></div></div></div><a class="indexterm" name="d0e23238"></a><p>
The <code class="literal">mysql</code> dictionary also understands the following
properties:
</p><div class="itemizedlist"><ul type="disc"><li><p><a name="MySQLDictionary.DriverDeserializesBlobs"></a>
<a class="indexterm" name="d0e23252"></a>
<code class="literal">DriverDeserializesBlobs</code>: Many older MySQL drivers
automatically deserialize BLOBs on calls to
<code class="methodname">ResultSet.getObject</code>. The
<code class="classname">MySQLDictionary</code> overrides the standard <code class="methodname">
DBDictionary.getBlobObject</code> method to take this into account.
Defaults to <code class="literal">true</code> if driver version is less than 5.0,
<code class="literal">false</code> otherwise. If your driver deserializes
automatically, you may want to set this property to <code class="literal">true</code>.
</p></li><li><p><a name="MySQLDictionary.TableType"></a>
<a class="indexterm" name="d0e23282"></a>
<code class="literal">TableType</code>: The MySQL table type to use when creating tables.
Defaults to <code class="literal">"innodb"</code>.
</p></li><li><p><a name="MySQLDictionary.UseClobs"></a>
<a class="indexterm" name="d0e23297"></a>
<code class="literal">UseClobs</code>: Some older versions of MySQL do not handle CLOBs
correctly. To disable CLOB functionality, set this to <code class="literal">false</code>.
Defaults to <code class="literal">true</code>.
</p></li><li><p><a name="MySQLDictionary.OptimizeMultiTableDeletes"></a>
<a class="indexterm" name="d0e23315"></a>
<code class="literal">OptimizeMultiTableDeletes</code>: MySQL as of version 4.0.0
supports multiple tables in <code class="literal">DELETE</code> statements. When
this option is set, OpenJPA will use that syntax when doing bulk deletes
from multiple tables. This can happen when the
<code class="literal">deleteTableContents</code> <code class="literal">SchemaTool</code>
action is used. (See <a href="ref_guide_schema_schematool.html" title="13.&nbsp; Schema Tool">Section&nbsp;13, &#8220;
Schema Tool
&#8221;</a> for
more info about <code class="literal">deleteTableContents</code>.) Defaults to
<code class="literal">false</code>, since the statement may fail if using InnoDB
tables and delete constraints.
</p></li></ul></div><p>
Starting with Connector/J 3.1.7, MySQL supports a variant of the driver
<code class="literal">com.mysql.jdbc.ReplicationDriver</code> that automatically sends
queries to a read/write master, or a failover or round-robin load balanced set
of slaves based on the state of read-only status of the connection.
See <a xmlns:xlink="http://www.w3.org/1999/xlink" href="http://dev.mysql.com/doc/refman/5.1/en/connector-j-reference-replication-connection.html" target="_top">
MySQL Reference</a> for more details.
</p><p>
This replication feature can be used transparently with OpenJPA application by
following configuration:
</p><div class="itemizedlist"><ul type="disc"><li><p>
<code class="literal">openjpa.ConnectionDriverName: com.mysql.jdbc.ReplicationDriver</code>
</p></li><li><p>
<code class="literal">openjpa.ConnectionFactoryProperties: autoReconnect=true,roundRobinLoadBalance=true</code>
</p><p>
OpenJPA will use a read-only connection with replicated database configuration
and will automatically switch the connection to a non-readonly mode if the
transaction is writing to the database.
</p></li></ul></div></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="ref_guide_dbsetup_dbsupport_oracle"></a>4.4.&nbsp;
OracleDictionary Properties
</h3></div></div></div><a class="indexterm" name="d0e23369"></a><p>
The <code class="literal">oracle</code> dictionary understands the following additional
properties:
</p><div class="itemizedlist"><ul type="disc"><li><p><a name="OracleDictionary.UseTriggersForAutoAssign"></a>
<a class="indexterm" name="d0e23383"></a>
<a class="indexterm" name="d0e23389"></a>
<code class="literal">UseTriggersForAutoAssign</code>: When true, OpenJPA will allow
simulation of auto-increment columns by the use of Oracle triggers. OpenJPA will
assume that the current sequence value from the sequence specified in the
<code class="literal">AutoAssignSequenceName</code> parameter will hold the value of the
new primary key for rows that have been inserted. For more details on
auto-increment support, see <a href="ref_guide_pc_oid.html#ref_guide_pc_oid_pkgen_autoinc" title="4.4.&nbsp; Autoassign / Identity Strategy Caveats">Section&nbsp;4.4, &#8220;
Autoassign / Identity Strategy Caveats
&#8221;</a>
.
</p></li><li><p><a name="OracleDictionary.AutoAssignSequenceName"></a>
<a class="indexterm" name="d0e23408"></a>
<a class="indexterm" name="d0e23414"></a>
<code class="literal">AutoAssignSequenceName</code>: The global name of the sequence that
OpenJPA will assume to hold the value of primary key value for rows that use
auto-increment. If left unset, OpenJPA will use a sequence named <code class="literal">
"&lt;table name&gt;_&lt;column name&gt;_SEQ"</code>.
</p></li><li><p><a name="OracleDictionary.MaxEmbeddedBlobSize"></a>
<a class="indexterm" name="d0e23431"></a>
<a class="indexterm" name="d0e23437"></a>
<code class="literal">MaxEmbeddedBlobSize</code>: Oracle is unable to persist BLOBs using
the embedded update method when BLOBs get over a certain size. The size depends
on database configuration, e.g. encoding. This property defines the maximum size
BLOB to persist with the embedded method. Defaults to 4000 bytes.
</p></li><li><p><a name="OracleDictionary.MaxEmbeddedClobSize"></a>
<a class="indexterm" name="d0e23449"></a>
<a class="indexterm" name="d0e23455"></a>
<code class="literal">MaxEmbeddedClobSize</code>: Oracle is unable to persist CLOBs using
the embedded update method when CLOBs get over a certain size. The size depends
on database configuration, e.g. encoding. This property defines the maximum size
CLOB to persist with the embedded method. Defaults to 4000 characters.
</p></li><li><p><a name="OracleDictionary.UseSetFormOfUseForUnicode"></a>
<code class="literal">UseSetFormOfUseForUnicode</code>: Prior to Oracle 10i, statements
executed against unicode capable columns (the <code class="literal">NCHAR</code>,
<code class="literal">NVARCHAR</code>, <code class="literal">NCLOB</code> Oracle types) required
special handling to be able to store unicode values. Setting this property to
<code class="literal">true</code> (the default) will cause OpenJPA to attempt to detect when the column is
one of these types, and if so, will attempt to correctly configure the statement
using the <code class="methodname"> OraclePreparedStatement.setFormOfUse</code>. For
more details, see the Oracle
<a xmlns:xlink="http://www.w3.org/1999/xlink" href="http://www.oracle.com/technology/sample_code/tech/java/codesnippet/jdbc/nchar/readme.html" target="_top">
Readme For NChar</a>. Note that this can only work if OpenJPA is able to
access the underlying <code class="classname">OraclePreparedStatement</code> instance,
which may not be possible when using some third-party datasources. If OpenJPA
detects that this is the case, a warning will be logged.
</p></li></ul></div></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="ref_guide_dbsetup_dbsupport_sybase"></a>4.5.&nbsp;
SybaseDictionary Properties
</h3></div></div></div><a class="indexterm" name="d0e23494"></a><p>
The <code class="literal">sybase</code> dictionary understands the following additional
properties:
</p><div class="itemizedlist"><ul type="disc"><li><p><a name="SybaseDictionary.IgnoreNumericTruncation"></a>
<a class="indexterm" name="d0e23508"></a>
<code class="literal">IgnoreNumericTruncation</code>: If true, Sybase will ignore numeric
truncation on SQL operations. Otherwise, if numeric truncation is detected,
the operation will fail.
</p></li></ul></div></div><div class="section" lang="en"><div class="titlepage"><div><div><h3 class="title"><a name="ref_guide_dbsetup_dbsupport_delim_id"></a>4.6.&nbsp;
Delimited Identifiers Support
</h3></div></div></div><p>
OpenJPA provides support for delimited identifiers as defined in the 2.0 JPA specification.
Identifiers can either be automatically delimited or individually manually
delimited. To have OpenJPA automatically delimit identifiers, add the
<code class="literal">&lt;delimited-identifiers/&gt;</code> tag
to the mapping file as documented in the JPA specification.
</p><p>
You can manually delimit individual identifiers either in the annotations or in the
definitions in the mapping file. To delimit an identifier element in an annotation,
surround it with double quotes. In a mapping file, add
<code class="literal">&amp;quote;</code> to both the beginning and end of the element.
</p><p>
When delimited identifiers has been specified, OpenJPA will delimit SQL identifiers
in the generated SQL statements. It will use database-specific delimiters as defined
in the appropriate database dictionary. By default, the leading and trailing
delimiters are both double quotes, <code class="literal">(")</code>. Different defaults for other
dictionaries provided by OpenJPA are in the following table.
</p><div class="table"><a name="d0e23535"></a><p class="title"><b>Table&nbsp;4.1.&nbsp;
Default delimiters for delimited identifiers
</b></p><div class="table-contents"><table summary="&#xA; Default delimiters for delimited identifiers&#xA; " border="1"><colgroup><col align="left"><col align="left"><col align="left"></colgroup><thead><tr><th align="left">
Dictionary
</th><th align="left">
Leading Delimiter
</th><th align="left">
Trailing Delimiter
</th></tr></thead><tbody><tr><td align="left">
MySQLDictionary
</td><td align="center">
`
</td><td align="center">
`
</td></tr><tr><td align="left">
AccessDictionary
</td><td align="center">
[
</td><td align="center">
]
</td></tr></tbody></table></div></div><br class="table-break"><p>
Some databases support more than one set of delimiters, often based on configuration.
If you need values different than the default values, you can set the
<a href="ref_guide_dbsetup_dbsupport.html#DBDicationary.LeadingDelimiter"><code class="literal">LeadingDelimiter</code></a>
and the
<a href="ref_guide_dbsetup_dbsupport.html#DBDicationary.TrailingDelimiter"><code class="literal">TrailingDelimiter</code></a>
dictionary properties.
</p><p>
You can specify whether or not the particular database that you are using supports delimited
identifiers by setting the
<a href="ref_guide_dbsetup_dbsupport.html#DBDictionary.SupportsDelimitedIdentifiers"><code class="literal">SupportsDelimitedIdentifiers</code></a>
dictionary property. If this value is set to <code class="literal">false</code>, identifiers will not be automatically
delimited, even if the <code class="literal">&lt;delimited-identifiers/&gt;</code> tag is specified
in the mapping file.
</p><p>
<code class="literal">Limitation:</code> The <code class="literal">columnDefinition</code> elements in identifiers
are not automatically delimited by OpenJPA when using the
<code class="literal">&lt;delimited-identifiers/&gt;</code> tag
in the mapping file. If you want these to be delimited, you must manually delimit them in
the annotation or mapping file definitions.
</p></div></div><div class="navfooter"><hr><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="ref_guide_dbsetup_sqlconn.html">Prev</a>&nbsp;</td><td width="20%" align="center"><a accesskey="u" href="ref_guide_dbsetup.html">Up</a></td><td width="40%" align="right">&nbsp;<a accesskey="n" href="ref_guide_dbsetup_isolation.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">3.&nbsp;
Runtime Access to DataSource
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Setting the Transaction Isolation
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