components/camel-sql/src/main/docs/sql-stored-component.adoc

= SQL Stored Procedure Component
:doctitle: SQL Stored Procedure
:shortname: sql-stored
:artifactid: camel-sql
:description: Perform SQL queries as a JDBC Stored Procedures using Spring JDBC.
:since: 2.17
:supportlevel: Stable
:tabs-sync-option:
:component-header: Only producer is supported
//Manually maintained attributes
:camel-spring-boot-name: sql

*Since Camel {since}*

*{component-header}*

The SQL Stored component allows you to work with databases using JDBC
Stored Procedure queries. This component is an extension to
the xref:sql-component.adoc[SQL Component] but specialized for calling
stored procedures.

This component uses `spring-jdbc` behind the scenes for the actual SQL
handling.

Maven users will need to add the following dependency to their `pom.xml`
for this component:

[source,xml]
----
<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-sql</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>
----

== URI format

The SQL component uses the following endpoint URI notation:

----
sql-stored:template[?options]
----

Where template is the stored procedure template, where you declare the
name of the stored procedure and the IN, INOUT, and OUT arguments. 

You can also refer to the template in an external file on the file system
or classpath such as:

----
sql-stored:classpath:sql/myprocedure.sql[?options]
----

Where `sql/myprocedure.sql` is a plain text file in the classpath with the
template, as show:

[source,sql]
----
SUBNUMBERS(
  INTEGER :#num,
  INTEGER :#num2,
  INOUT INTEGER :#num3 out1,
  OUT INTEGER out2
)
----



// component options: START
include::partial$component-configure-options.adoc[]
include::partial$component-endpoint-options.adoc[]
include::partial$component-endpoint-headers.adoc[]
// component options: END


== Usage

=== Declaring the stored procedure template

The template is declared using a syntax that would be similar to a Java
method signature. The name of the stored procedure, and then the
arguments enclosed in parentheses. An example explains this well:

[source,xml]
----
<to uri="sql-stored:STOREDSAMPLE(INTEGER ${headers.num1},INTEGER ${headers.num2},INOUT INTEGER ${headers.num3} result1,OUT INTEGER result2)"/>
----

The arguments are declared by a type and then a mapping to the Camel
message using simple expression. So, in this example, the first two
parameters are `IN` values of `INTEGER` type, mapped to the message
headers. The third parameter is `INOUT`, meaning it accepts an `INTEGER`
and then returns a different `INTEGER` result. The last parameter is
the `OUT` value, also an `INTEGER` type.

In SQL terms, the stored procedure could be declared as:

[source,sql]
----
CREATE PROCEDURE STOREDSAMPLE(VALUE1 INTEGER, VALUE2 INTEGER, INOUT RESULT1 INTEGER, OUT RESULT2 INTEGER)
----

==== IN Parameters

IN parameters take four parts separated by a space: parameter name, SQL type (with scale), type name, and value source.

Parameter name is optional and will be auto generated if not provided. It must be given between quotes(').

SQL type is required and can be an integer (positive or negative) or reference to integer field in some class.
If SQL type contains a dot, then the component tries to resolve that class and read the given field. For example,
SQL type `com.Foo.INTEGER` is read from the field `INTEGER` of class `com.Foo`. If the type doesn't
contain comma then class to resolve the integer value will be `java.sql.Types`.
Type can be postfixed by scale for example `DECIMAL(10)` would mean `java.sql.Types.DECIMAL` with scale 10.

Type name is optional and must be given between quotes(').

Value source is required. Value source populates the parameter value from the Exchange.
It can be either a Simple expression or header location i.e. `:#<header name>`. For example,
the Simple expression `${header.val}` would mean that parameter value will be read from the header `val`.
Header location expression `:#val` would have identical effect.

When using named parameters, Camel will look up the names in the given precedence:

1. from a xref:languages:simple-language.adoc[Simple] expressions
2. from message body if it is a `java.util.Map`
3. from message headers
4. from exchange variables

[source,xml]
----
<to uri="sql-stored:MYFUNC('param1' org.example.Types.INTEGER(10) ${header.srcValue})"/>
----

URI means that the stored procedure will be called with parameter name `param1`,
it's SQL type is read from field `INTEGER` of class `org.example.Types` and scale will be set to 10.
The input value for the parameter is passed from the header `srcValue`.

[source,xml]
----------------------------------------------------------------------------------------------------------
<to uri="sql-stored:MYFUNC('param1' 100 'mytypename' ${header.srcValue})"/>
----------------------------------------------------------------------------------------------------------
URI is identical to previous on except SQL-type is 100 and type name is _mytypename_.

Actual call will be done using org.springframework.jdbc.core.SqlParameter.

==== OUT Parameters

OUT parameters work similarly IN parameters and contain three parts: SQL type(with scale), type name, and output parameter name.

SQL type works the same as IN parameters.

Type name is optional and also works the same as IN parameters.

Output parameter name is used for the OUT parameter name, as well as the header name where the result will be stored.

[source,xml]
----
<to uri="sql-stored:MYFUNC(OUT org.example.Types.DECIMAL(10) outheader1)"/>
----

URI means that the OUT parameter's name is `outheader1` and result will be but into header `outheader1`.

[source,xml]
----
<to uri="sql-stored:MYFUNC(OUT org.example.Types.NUMERIC(10) 'mytype' outheader1)"/>
----

This is identical to previous one but type name will be `mytype`.

Actual call will be done using `org.springframework.jdbc.core.SqlOutParameter`.

==== INOUT Parameters

INOUT parameters are a combination of all of the above.  They receive a value from the exchange, as well as store a
result as a message header.  The only caveat is that the IN parameter's "name" is skipped.  Instead, the OUT
parameter's _name_ defines both the SQL parameter name, and the result header name.

[source,xml]
----
<to uri="sql-stored:MYFUNC(INOUT DECIMAL(10) ${headers.inheader} outheader)"/>
----

Actual call will be done using org.springframework.jdbc.core.SqlInOutParameter.

==== Query Timeout

You can configure query timeout (via `template.queryTimeout`) on statements used for query processing as shown:

[source,xml]
----
<to uri="sql-stored:MYFUNC(INOUT DECIMAL(10) ${headers.inheader} outheader)?template.queryTimeout=5000"/>
----

This will be overridden by the remaining transaction timeout when executing within a transaction that has a timeout specified at the transaction level.


=== Camel SQL Starter

A starter module is available to spring-boot users. When using the starter,
the `DataSource` can be directly configured using spring-boot properties.

[source,properties]
----
# Example for a mysql datasource
spring.datasource.url=jdbc:mysql://localhost/test
spring.datasource.username=dbuser
spring.datasource.password=dbpass
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
----

To use this feature, add the following dependencies to your spring boot pom.xml file:

[source,xml]
----
<dependency>
    <groupId>org.apache.camel.springboot</groupId>
    <artifactId>camel-sql-starter</artifactId>
    <version>${camel.version}</version> <!-- use the same version as your Camel core version -->
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
    <version>${spring-boot-version}</version>
</dependency>
----

You should also include the specific database driver, if needed.



include::spring-boot:partial$starter.adoc[]