layout: docs title: JSON Reference sidebar_title: JSON Reference permalink: /docs/json_reference.html requests:
As Avatica uses JSON to serialize messages sent over an HTTP transport, the RPC layer is agnostic of the language used by a client. While the Avatica server is written in Java, this enables clients to interact with the server using any language instead of being limited to Java.
A specification of the JSON request and response objects are documented below. Programmatic bindings for these JSON objects are only available in Java. For support outside of Java, see the Protocol Buffer [bindings]({{ site.baseurl }}/docs/avatica_protobuf_reference.html)
The collection of all JSON objects accepted as requests to Avatica. All Requests include a request attribute which uniquely identifies the concrete Request from all other Requests.
This request is used to fetch the available catalog names in the database.
{% highlight json %} { “request”: “getCatalogs”, “connectionId”: “000000-0000-0000-00000000” } {% endhighlight %}
connectionId (required string) The identifier of the connection to use.
This request is used to close the Connection object in the Avatica server identified by the given IDs.
{% highlight json %} { “request”: “closeConnection”, “connectionId”: “000000-0000-0000-00000000” } {% endhighlight %}
connectionId (required string) The identifier of the connection to close.
This request is used to close the Statement object in the Avatica server identified by the given IDs.
{% highlight json %} { “request”: “closeStatement”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345 } {% endhighlight %}
connectionId (required string) The identifier of the connection to which the statement belongs.
statementId (required integer) The identifier of the statement to close.
This request is used to fetch columns in the database given some optional filtering criteria.
{% highlight json %} { “request”: “getColumns”, “connectionId”: “000000-0000-0000-00000000”, “catalog”: “catalog”, “schemaPattern”: “schema_pattern.*”, “tableNamePattern”: “table_pattern.*”, “columnNamePattern”: “column_pattern.*” } {% endhighlight %}
connectionId (required string) The identifier of the connection on which to fetch the columns.
catalog (optional string) The name of a catalog to limit returned columns.
schemaPattern (optional string) A Java Pattern against schemas to limit returned columns.
tableNamePattern (optional string) A Java Pattern against table names to limit returned columns.
columnNamePattern (optional string) A Java Pattern against column names to limit returned columns.
This request is used to issue a commit on the Connection in the Avatica server identified by the given ID.
{% highlight json %} { “request”: “commit”, “connectionId”: “000000-0000-0000-00000000” } {% endhighlight %}
connectionId (required string) The identifier of the connection on which to invoke commit.
This request is used to ensure that the client and server have a consistent view of the database properties.
{% highlight json %} { “request”: “connectionSync”, “connectionId”: “000000-0000-0000-00000000”, “connProps”: ConnectionProperties } {% endhighlight %}
connectionId (required string) The identifier of the connection to synchronize.
connProps (optional nested object) A ConnectionProperties object to synchronize between the client and server.
This request is used to create a new Statement in the Avatica server.
{% highlight json %} { “request”: “createStatement”, “connectionId”: “000000-0000-0000-00000000” } {% endhighlight %}
connectionId (required string) The identifier of the connection to use in creating a statement.
This request is used to fetch all database properties.
{% highlight json %} { “request”: “databaseProperties”, } {% endhighlight %}
connectionId (required string) The identifier of the connection to use when fetching the database properties.
This request is used to execute a batch of updates on a PreparedStatement.
{% highlight json %} { “request”: “executeBatch”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “parameterValues”: [ [ TypedValue, TypedValue, ... ], [ TypedValue, TypedValue, ...], ... ] } {% endhighlight %}
connectionId (required string) The identifier of the connection to use when fetching the database properties.
statementId (required integer) The identifier of the statement created using the above connection.
parameterValues (required array of array) An array of arrays of TypedValue's. Each element in the array is an update to a row, while the outer array represents the entire “batch” of updates.
This request is used to execute a PreparedStatement, optionally with values to bind to the parameters in the Statement.
{% highlight json %} { “request”: “execute”, “statementHandle”: StatementHandle, “parameterValues”: [TypedValue, TypedValue, ... ], “maxRowCount”: 100 } {% endhighlight %}
statementHandle (required object) A StatementHandle object.
parameterValues (optional array of nested objects) The TypedValue for each parameter on the prepared statement.
maxRowCount (required long) The maximum number of rows returned in the response.
This request is used to fetch a batch of rows from a Statement previously created.
{% highlight json %} { “request”: “fetch”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “offset”: 0, “fetchMaxRowCount”: 100 } {% endhighlight %}
connectionId (required string) The identifier of the connection to use.
statementId (required integer) The identifier of the statement created using the above connection.
offset (required integer) The positional offset into a result set to fetch.
fetchMatchRowCount (required integer) The maximum number of rows to return in the response to this request.
This request is used to open a new Connection in the Avatica server.
{% highlight json %} { “request”: “openConnection”, “connectionId”: “000000-0000-0000-00000000”, “info”: {“key”:“value”, ...} } {% endhighlight %}
connectionId (required string) The identifier of the connection to open in the server.
info (optional string-to-string map) A Map containing properties to include when creating the Connection.
This request is used as short-hand to create a Statement and execute an batch of SQL commands in that Statement.
{% highlight json %} { “request”: “prepareAndExecuteBatch”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “sqlCommands”: [ “SQL Command”, “SQL Command”, ... ] } {% endhighlight %}
connectionId (required string) The identifier for the connection to use.
statementId (required integer) The identifier for the statement created by the above connection to use.
sqlCommands (required array of strings) An array of SQL commands
This request is used as a short-hand for create a Statement and fetching the first batch of results in a single call without any parameter substitution.
{% highlight json %} { “request”: “prepareAndExecute”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “sql”: “SELECT * FROM table”, “maxRowCount”: 100, } {% endhighlight %}
connectionId (required string) The identifier for the connection to use.
statementId (required integer) The identifier for the statement created by the above connection to use.
sql (required string) A SQL statement
maxRowCount (required long) The maximum number of rows returned in the response.
This request is used to create create a new Statement with the given query in the Avatica server.
{% highlight json %} { “request”: “prepare”, “connectionId”: “000000-0000-0000-00000000”, “sql”: “SELECT * FROM table”, “maxRowCount”: 100, } {% endhighlight %}
connectionId (required string) The identifier for the connection to use.
sql (required string) A SQL statement
maxRowCount (required long) The maximum number of rows returned in the response.
This request is used to reset a ResultSet's iterator to a specific offset in the Avatica server.
{% highlight json %} { “request”: “syncResults”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “state”: QueryState, “offset”: 200 } {% endhighlight %}
connectionId (required string) The identifier for the connection to use.
statementId (required integer) The identifier for the statement to use.
state (required object) The QueryState object.
offset (required long) The offset into the ResultSet to seek to.
This request is used to issue a rollback on the Connection in the Avatica server identified by the given ID.
{% highlight json %} { “request”: “rollback”, “connectionId”: “000000-0000-0000-00000000” } {% endhighlight %}
connectionId (required string) The identifier for the connection on which to invoke rollback.
This request is used to fetch the schemas matching the provided criteria in the database.
{% highlight json %} { “request”: “getSchemas”, “connectionId”: “000000-0000-0000-00000000”, “catalog”: “name”, “schemaPattern”: “pattern.*” } {% endhighlight %}
connection_id The identifier for the connection to fetch schemas from.
catalog (required string) The name of the catalog to fetch the schema from.
schemaPattern (required string) A Java pattern of schemas to fetch.
This request is used to fetch the table types available in this database.
{% highlight json %} { “request”: “getTableTypes”, “connectionId”: “000000-0000-0000-00000000” } {% endhighlight %}
connectionId The identifier of the connection to fetch the table types from.
This request is used to fetch the tables available in this database filtered by the provided criteria.
{% highlight json %} { “request”: “getTables”, “connectionId”: “000000-0000-0000-00000000”, “catalog”: “catalog_name”, “schemaPattern”: “schema_pattern.*”, “tableNamePattern”: “table_name_pattern.*”, “typeList”: [ “TABLE”, “VIEW”, ... ] } {% endhighlight %}
catalog (optional string) The name of a catalog to restrict fetched tables.
connectionId The identifier of the connection to fetch the tables from.
schemaPattern (optional string) A Java Pattern representing schemas to include in fetched tables.
tableNamePattern (optional string) A Java Pattern representing table names to include in fetched tables.
typeList (optional array of string) A list of table types used to restrict fetched tables.
This request is used to fetch the types available in this database.
{% highlight json %} { “request”: “getTypeInfo”, “connectionId”: “000000-0000-0000-00000000” } {% endhighlight %}
connectionId The identifier of the connection to fetch the types from.
The collection of all JSON objects returned as responses from Avatica. All Responses include a response attribute which uniquely identifies the concrete Response from all other Responses.
A response to the CloseConnectionRequest.
{% highlight json %} { “response”: “closeConnection”, “rpcMetadata”: RpcMetadata } {% endhighlight %}
rpcMetadata Server metadata about this call.
A response to the CloseStatementRequest.
{% highlight json %} { “response”: “closeStatement”, “rpcMetadata”: RpcMetadata } {% endhighlight %}
rpcMetadata Server metadata about this call.
A response to the CommitRequest.
{% highlight json %} { “response”: “commit” } {% endhighlight %}
There are no extra attributes on this Response.
A response to the ConnectionSyncRequest. Properties included in the response are those of the Connection in the Avatica server.
{% highlight json %} { “response”: “connectionSync”, “connProps”: ConnectionProperties, “rpcMetadata”: RpcMetadata } {% endhighlight %}
connProps The ConnectionProperties that were synchronized.
rpcMetadata Server metadata about this call.
A response to the CreateStatementRequest. The ID of the statement that was created is included in the response. Clients will use this statementId in subsequent calls.
{% highlight json %} { “response”: “createStatement”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “rpcMetadata”: RpcMetadata } {% endhighlight %}
connectionId The identifier for the connection used to create the statement.
statementId The identifier for the created statement.
rpcMetadata Server metadata about this call.
A response to the DatabasePropertyRequest. See DatabaseProperty for information on the available property keys.
{% highlight json %} { “response”: “databaseProperties”, “map”: { DatabaseProperty: Object, DatabaseProperty: Object, ... }, “rpcMetadata”: RpcMetadata } {% endhighlight %}
map A map of DatabaseProperty to value of that property. The value may be some primitive type or an array of primitive types.
rpcMetadata Server metadata about this call.
A response when an error was caught executing a request. Any request may return this response.
{% highlight json %} { “response”: “error”, “exceptions”: [ “stacktrace”, “stacktrace”, ... ], “errorMessage”: “The error message”, “errorCode”: 42, “sqlState”: “ABC12”, “severity”: AvaticaSeverity, “rpcMetadata”: RpcMetadata } {% endhighlight %}
exceptions A list of stringified Java StackTraces.
errorMessage A human-readable error message.
errorCode A numeric code for this error.
sqlState A five character alphanumeric code for this error.
severity An AvaticaSeverity object which denotes how critical the error is.
rpcMetadata Server metadata about this call.
A response to ExecuteBatchRequest and PrepareAndExecuteRequest which encapsulates the update counts for a batch of updates.
{% highlight json %} { “response”: “executeBatch”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “updateCounts”: [ 1, 1, 0, 1, ... ], “missingStatement”: false, “rpcMetadata”: RpcMetadata } {% endhighlight %}
connectionId The identifier for the connection used to create the statement.
statementId The identifier for the created statement.
updateCounts An array of integers corresponding to each update contained in the batch that was executed.
missingStatement True if the operation failed because the Statement is not cached in the server, false otherwise.
rpcMetadata Server metadata about this call.
A response to the ExecuteRequest which contains the results for a metadata query.
{% highlight json %} { “response”: “executeResults”, “resultSets”: [ ResultSetResponse, ResultSetResponse, ... ], “missingStatement”: false, “rpcMetadata”: RpcMetadata } {% endhighlight %}
resultSets An array of ResultSetResponses.
missingStatement A boolean which denotes if the request failed due to a missing Statement.
rpcMetadata Server metadata about this call.
A response to the FetchRequest which contains the request for the query.
{% highlight json %} { “response”: “fetch”, “frame”: Frame, “missingStatement”: false, “missingResults”: false, “rpcMetadata”: RpcMetadata } {% endhighlight %}
frame A Frame containing the results of the fetch.
missingStatement A boolean which denotes if the request failed due to a missing Statement.
missingResults A boolean which denotes if the request failed due to a missing ResultSet.
rpcMetadata Server metadata about this call.
A response to the OpenConnectionRequest. The ID for the connection that the client should use in subsequent calls was provided by the client in the request.
{% highlight json %} { “response”: “openConnection”, “rpcMetadata”: RpcMetadata } {% endhighlight %}
rpcMetadata Server metadata about this call.
A response to the PrepareRequest. This response includes a StatementHandle which clients must use to fetch the results from the Statement.
{% highlight json %} { “response”: “prepare”, “statement”: StatementHandle, “rpcMetadata”: RpcMetadata } {% endhighlight %}
statement A StatementHandle object.
rpcMetadata Server metadata about this call.
A response which contains the results and type details from a query.
{% highlight json %} { “response”: “resultSet”, “connectionId”: “000000-0000-0000-00000000”, “statementId”: 12345, “ownStatement”: true, “signature”: Signature, “firstFrame”: Frame, “updateCount”: 10, “rpcMetadata”: RpcMetadata } {% endhighlight %}
connectionId The identifier for the connection used to generate this response.
statementId The identifier for the statement used to generate this response.
ownStatement Whether the result set has its own dedicated statement. If true, the server must automatically close the statement when the result set is closed. This is used for JDBC metadata result sets, for instance.
signature A non-optional nested object Signature
firstFrame A optional nested object Frame
updateCount A number which is always -1 for normal result sets. Any other value denotes a “dummy” result set that only contains this count and no additional data.
rpcMetadata Server metadata about this call.
A response to the RollBackRequest.
{% highlight json %} { “response”: “rollback” } {% endhighlight %}
There are no extra attributes on this Response.
A response to the SyncResultsRequest. When moreResults is true, a FetchRequest should be issued to get the next batch of records. When missingStatement is true, the statement must be re-created using PrepareRequest or the appropriate Request for a DDL request (e.g. CatalogsRequest or SchemasRequest).
{% highlight json %} { “response”: “syncResults”, “moreResults”: true, “missingStatement”: false, “rpcMetadata”: RpcMetadata } {% endhighlight %}
moreResults A boolean which denotes if results exist for the ResultSet being “synced” per the request.
missingStatement A boolean which denotes if the statement for the ResultSet still exists.
rpcMetadata Server metadata about this call.
This object describes the “simple”, or scalar, JDBC type representation of a column in a result. This does not include complex types such as arrays.
{% highlight json %} { “signed”: true, “precision”: 10, “scale”: 2, “parameterType”: 8, “typeName”: “integer”, “className”: “java.lang.Integer”, “name”: “number” } {% endhighlight %}
signed A boolean denoting whether the column is a signed numeric.
precision The maximum numeric precision supported by this column.
scale The maximum numeric scale supported by this column.
parameterType An integer corresponding to the JDBC Types class denoting the column's type.
typeName The JDBC type name for this column.
className The Java class backing the JDBC type for this column.
name The name of the column.
This enumeration describes the various levels of concern for an error in the Avatica server.
One of:
UNKNOWNFATALERRORWARNINGThis object describes a simple or complex type for a column. Complex types will contain additional information in the component or columns attribute which describe the nested types of the complex parent type.
{% highlight json %} { “type”: “scalar”, “id”: “identifier”, “name”: “column”, “rep”: Rep, “columns”: [ ColumnMetaData, ColumnMetaData, ... ], “component”: AvaticaType } {% endhighlight %}
type One of: scalar, array, struct.
id A numeric value corresponding to the type of the object per the JDBC Types class.
name The readable name of the JDBC type.
rep A nested Rep object used by Avatica to hold additional type information.
columns For STRUCT types, a list of the columns contained in that STRUCT.
component For ARRAY types, the type of the elements contained in that ARRAY.
This object represents the JDBC ResultSetMetaData for a column.
{% highlight json %} { “ordinal”: 0, “autoIncrement”: true, “caseSensitive”: true, “searchable”: false, “currency”: false, “nullable”: 0, “signed”: true, “displaySize”: 20, “label”: “Description”, “columnName”: “col1”, “schemaName”: “schema”, “precision”: 10, “scale”: 2, “tableName”: “table”, “catalogName”: “catalog”, “type”: AvaticaType, “readOnly”: false, “writable”: true, “definitelyWritable”: true, “columnClassName”: “java.lang.String” } {% endhighlight %}
ordinal A positional offset number.
autoIncrement A boolean denoting whether the column is automatically incremented.
caseSensitive A boolean denoting whether the column is case sensitive.
searchable A boolean denoting whether this column supports all WHERE search clauses.
currency A boolean denoting whether this column represents currency.
nullable A number denoting whether this column supports null values.
signed A boolean denoting whether the column is a signed numeric.
displaySize The character width of the column.
label A description for this column.
columnName The name of the column.
schemaName The schema to which this column belongs.
precision The maximum numeric precision supported by this column.
scale The maximum numeric scale supported by this column.
tableName The name of the table to which this column belongs.
catalogName The name of the catalog to which this column belongs.
type A nested AvaticaType representing the type of the column.
readOnly A boolean denoting whether the column is read-only.
writable A boolean denoting whether the column is possible to be updated.
definitelyWritable A boolean denoting whether the column definitely can be updated.
columnClassName The name of the Java class backing the column's type.
This object represents the properties for a given JDBC Connection.
{% highlight json %} { “connProps”: “connPropsImpl”, “autoCommit”: true, “readOnly”: true, “transactionIsolation”: 0, “catalog”: “catalog”, “schema”: “schema” } {% endhighlight %}
autoCommit (optional boolean) A boolean denoting if autoCommit is enabled for transactions.
readOnly (optional boolean) A boolean denoting if a JDBC connection is read-only.
transactionIsolation (optional integer) An integer which denotes the level of transactions isolation per the JDBC specification. This value is analogous to the values defined in java.sql.Connection.
catalog (optional string) The name of the catalog to include when fetching connection properties.
schema (optional string) The name of the schema to include when fetching connection properties.
This object represents the information required to cast untyped objects into the necessary type for some results.
{% highlight json %} { “style”: Style, “clazz”: “java.lang.String”, “fieldNames”: [ “column1”, “column2”, ... ] } {% endhighlight %}
style A string denoting the Style of the contained objects.
This object represents the exposed database properties for a Connection through the Avatica server.
One of:
GET_STRING_FUNCTIONSGET_NUMERIC_FUNCTIONSGET_SYSTEM_FUNCTIONSGET_TIME_DATE_FUNCTIONSGET_S_Q_L_KEYWORDSGET_DEFAULT_TRANSACTION_ISOLATIONThis object represents a batch of results, tracking the offset into the results and whether more results still exist to be fetched in the Avatica server.
{% highlight json %} { “offset”: 100, “done”: true, “rows”: [ [ val1, val2, ... ], ... ] } {% endhighlight %}
offset The starting position of these rows in the encompassing result set.
done A boolean denoting whether more results exist for this result set.
rows An array of arrays corresponding to the rows and columns for the result set.
This object represents the way a ResultSet was created in the Avatica server. A ResultSet could be created by a user-provided SQL or by a DatabaseMetaData operation with arguments on that operation.
{% highlight json %} { “type”: StateType, “sql”: “SELECT * FROM table”, “metaDataOperation”: MetaDataOperation, “operationArgs”: [“arg0”, “arg1”, ... ] } {% endhighlight %}
type A StateType object denoting what type of operation backs the ResultSet for this query.
sql The SQL statement which created the ResultSet for this query. Required if the type is SQL.
metaDataOperation The DML operation which created the ResultSet for this query. Required if the type is METADATA.
operationArgs The arguments to the invoked DML operation. Required if the type is METADATA.
This enumeration represents the concrete Java type for some value.
One of:
PRIMITIVE_BOOLEANPRIMITIVE_BYTEPRIMITIVE_CHARPRIMITIVE_SHORTPRIMITIVE_INTPRIMITIVE_LONGPRIMITIVE_FLOATPRIMITIVE_DOUBLEBOOLEANBYTECHARACTERSHORTINTEGERLONGFLOATDOUBLEJAVA_SQL_TIMEJAVA_SQL_TIMESTAMPJAVA_SQL_DATEJAVA_UTIL_DATEBYTE_STRINGSTRINGNUMBEROBJECTThis object contains assorted per-call/contextual metadata returned by the Avatica server.
{% highlight json %} { “serverAddress”: “localhost:8765” } {% endhighlight %}
serverAddress The host:port of the server which created this object.
This object represents the result of preparing a Statement in the Avatica server.
{% highlight json %} { “columns”: [ ColumnMetaData, ColumnMetaData, ... ], “sql”: “SELECT * FROM table”, “parameters”: [ AvaticaParameter, AvaticaParameter, ... ], “cursorFactory”: CursorFactory, “statementType”: StatementType } {% endhighlight %}
columns An array of ColumnMetaData objects denoting the schema of the result set.
sql The SQL executed.
parameters An array of AvaticaParameter objects denoting type-specific details.
cursorFactory An CursorFactory object representing the Java representation of the frame.
statementType An StatementType object representing the type of Statement.
This enumeration denotes whether user-provided SQL or a DatabaseMetaData operation was used to create some ResultSet.
One of:
SQLMETADATAThis object encapsulates all of the information of a Statement created in the Avatica server.
{% highlight json %} { “connectionId”: “000000-0000-0000-00000000”, “id”: 12345, “signature”: Signature } {% endhighlight %}
connectionId The identifier of the connection to which this statement belongs.
id The identifier of the statement.
signature A Signature object for the statement.
This enumeration represents what kind the Statement is.
One of:
SELECTINSERTUPDATEDELETEUPSERTMERGEOTHER_DMLCREATEDROPALTEROTHER_DDLCALLThis enumeration represents the generic “class” of type for a value.
One of:
OBJECTRECORDRECORD_PROJECTIONARRAYLISTMAPThis object encapsulates the type and value for a column in a row.
{% highlight json %} { “type”: “type_name”, “value”: object } {% endhighlight %}
type A name referring to the type of the object stored in value.
value A JSON representation of a JDBC type.
The following chart documents how each Rep value is serialized into a JSON value. Consult the JSON documentation for more information on valid attributes in JSON.
| Rep Value | Serialized | Description | | PRIMITIVE_BOOLEAN | boolean || | BOOLEAN | boolean || | PRIMITIVE_BYTE | number | The numeric value of the byte. | | BYTE | number || | PRIMITIVE_CHAR | string || | CHARACTER | string || | PRIMITIVE_SHORT | number || | SHORT | number || | PRIMITIVE_INT | number || | INTEGER | number || | PRIMITIVE_LONG | number || | LONG | number || | PRIMITIVE_FLOAT | number || | FLOAT | number || | PRIMITIVE_DOUBLE | number || | DOUBLE | number || | BIG_INTEGER | number | Implicitly handled by Jackson. | | BIG_DECIMAL | number | Implicitly handled by Jackson. | | JAVA_SQL_TIME | number | As an integer, milliseconds since midnight. | | JAVA_SQL_DATE | number | As an integer, the number of days since the epoch. | | JAVA_SQL_TIMESTAMP | number | As a long, milliseconds since the epoch. | | JAVA_UTIL_DATE | number | As a long, milliseconds since the epoch. | | BYTE_STRING | string | A Base64-encoded string. | | STRING | string | | | NUMBER | number | A general number, unknown what concrete type. | | OBJECT | null | Implicitly converted by Jackson. | | NULL | null | Implicitly converted by Jackson. | | ARRAY | N/A | Implicitly handled by Jackson. | | STRUCT | N/A | Implicitly handled by Jackson. | | MULTISET | N/A | Implicitly handled by Jackson. |