{note}The SQL component executes SQL instructions, limited to the Data Manipulation Language, using JDBC.
It acts only as a service provider.{note}

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h1. Feature
{petalslink:author=llacote|type= FIXME SECTION A RELIRE ET COMPLETER}{petalslink}
The SQL component is a Binding Component (BC) which supports SQL instructions in Data Manipulation Language, through the Java Data Base Connectivity API (JDBC).

This component provides a set of X operations:

These operations are described in an embedded WSDL.
{info}All attachment are processed by using XOP rules.(XML-binary Optimized Packaging : [http://www.w3.org/TR/xop10/] ){info}

h1. Exposing a FTP connection as a service
{petalslink:author=llacote|type= FIXME SECTION A COMPLETER EN S'INSPIRANT DE LA DOC DU BC-FTP}

{petalslink}

h2. Usage

h3. Execute Operation
When the {{execute}} operation is set on the incoming message exchange, the component performs the SQL instructions contained in the IN message. If the execution returns information (an SQL SELECT for example), the OUT message contains the SQL ResultSet.
{info}If you want to see extra information on the response, you can set the show-metadata attribute to true. The response will contains row index, column name and type.{info}
The IN message looks like :
{code:xml}
<execute xmlns="http://petals.ow2.org/components/sql/version-1">
<sql show-metadata="true">SELECT name, firstname FROM user WHERE id='123'</sql>
{code}
The OUT message returned to the consumer contains the XML representation of the ResultSet returned by the SQL statement execution. If metadata have been enabled, their are set as attributes.
{code:xml}
<executeResponse xmlns="http://petals.ow2.org/components/sql/version-1">
<row index='1'>
<column name='name' type='varchar'>Field</column>
<column name='firstname' type='varchar'>Jean</column>
</row>
<row index='2'>
<column name='name' type='varchar'>Foo</column>
<column name='firstname' type='varchar'>John</column>
</row>
</executeResponse>
{info}The ResultSet can be written in the OUT message by a thread while the reponse message is sent back by another thread (pipes strreaming mechanism), increasing performance. To enable this feature, set the {{org.ow2.petals.transport.streaming=true}} property on the JBI Exchange, or set the {{streamingMode}} parameter of the Service Unit (in this case, the streaming mode is active for all requests).{info}
{info}The execute operation is defined in the SQL component abstract WSDL. You can import this abstract WSDL and define a concret WSDL to reference in your SU.{info}

{code}

h2. Configuration

{include:0 CDK Description of provide}

|| {color:#333333}Parameter{color} || {color:#333333}Description{color}\\ || {color:#333333}Default{color}\\ || {color:#333333}Required{color}\\ ||
| timeout | Timeout in milliseconds of a synchronous send. This parameter is used by the method {{sendSync}} (Exchange exchange) proposes by the CDK {{Listeners}} classes. \\
Set it to 0 for an infinite timeout. | 0 | No |
| retrypolicy | This section defines a policy when attempting external transfer of message, before accepting the service as failed.
{note}Only for Binding Components.{note} | \- | No |
| retrypolicy - attempts | The number of transfer attempts. | \- | bound to {{retrypolicy}} |
| retrypolicy - delay | The delay in milliseconds between transfer attempts. | \- | bound to {{retrypolicy}} |
| exchange-properties | This sections defines the list of properties to set to the JBI exchange when processing a service. | \- | No |
| message-properties | This sections defines the list of properties to set to the JBI message when processing a service. | | No |
| validate-wsdl | Activate the validation of the WSDL when deploying a service unit. | true | No |
| WSDL | Path to the WSDL document describing services and operations exposed by the provided JBI endpoints defined in the SU. \\
The value of this parameter is : \\
* an URL
* a file relative to the root of the SU package \\
If not specified, a basic WSDL description is automaticaly provided by the CDK. | | No |
| forward-attachments \\ | Defines if attachment will be forwarded. \\ | false \\ | No \\ |
| forward-message-properties \\ | Defines if the message properties will be forwarded. | false \\ | No \\ |
| forward-security-subject \\ | Defines if the security subject will be forwarded. | false \\ | No \\ |
| exchange-property - org.ow2.petals.router.provider.noack | Check Petals documentation for further details. This property activates the bypass of acknowledgement messages destinated to this SU. Can be used for MEPs {{RobustInOnly}}, {{InOut}} and {{InOptionalOut}}. | \- | bound to {{retrypolicy}} |
| org.ow2.petals.transport.compress | {warning}To be used only in distributed setup of Petals ESB. Check Petals ESB documentation for further details.{warning} This property activates the compression of the message payload when set to {{true}}. | true | No |
{table-plus}
{petalslink}{include:0 CDK SU Provide Configuration}{petalslink}

|| Parameter\\ || Description || Default value || Required ||
| url \\ | The JDBC URL of the targeted database \\ | \- \\ | Yes \\ |
| driver | The JDBC Driver className. The JDBC library has to be loaded with a SharedLibrary. It is automatically resolved for: mysql,oracle,hsql,sqlserver,derby,postgresql,db2,sybase (according to the jdbc url). | \-\\ | No\\ |
| user\\ | The database user\\ | \-\\ | Yes\\ |
| password\\ | The database password.\\ | \-\\ | Yes\\ |
| maxActive\\ | The maximum number of active connections that can be allocated from this pool at the same time, or negative for no limit. | 8\\ | No |
| maxIdle\\ | The maximum number of connections that can remain idle in the pool, without extra ones being released, or negative for no limit. | 8\\ | No |
| minIdle\\ | The minimum number of connections that can remain idle in the pool, without extra ones being created, or zero to create none. | 0\\ | No |
| maxWait\\ | The maximum amount of milliseconds that the pool will wait (when there are no available connections) for a connection to be returned before throwing an exception, \-1 to wait indefinitely. | \-1\\ | No |
| timeBetweenEvictionRunsMillis\\ | The number of milliseconds to sleep between runs of the idle object evictor thread. When non-positive, no idle object evictor thread will be run. | \-1\\ | No |
| metadata\\ | If true, When the 'select' operation is used, the response contains metadata on result elements(Row type,index...). | false\\ | No\\ |
{table-plus}

h3. Service Unit descriptor

The SQL component creates dataSource initialized with Service Unit parameters.
You have to deploy a Service Unit with a JBI descriptor containing a provides section and the following parameters.
Here is a sample of a SU JBI descriptor to configure a MyDataBaseSQL service.
{code:xml}
<jbi:jbi version="1.0"
xmlns:interfaceNs="http://petals.ow2.org/components/sql/version-1"
xmlns:jbi="http://java.sun.com/xml/ns/jbi"
xmlns:petalsCDK="http://petals.ow2.org/components/extensions/version-5"
xmlns:serviceNs="http://test"
xmlns:sql="http://petals.ow2.org/components/sql/version-1"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<!-- Import a Service into PEtALS or Expose a PEtALS Service => use a BC. -->
<jbi:services binding-component="true">
<!-- Import a Service into PEtALS => provides a Service. -->
<jbi:provides
interface-name="interfaceNs:SQLInterface"
service-name="serviceNs:MyDatabaseSQLService"
endpoint-name="MyDatabaseSQLServiceEndpoint">
<!-- CDK specific elements -->
<petalsCDK:wsdl>SQLService.wsdl</petalsCDK:wsdl>
<!-- Component specific elements -->
<sql:url>jdbc:mysql://host_name:port/dbname</sql:url>
<sql:user>test</sql:user>
<sql:password>test</sql:password>
<sql:maxActive>8</sql:maxActive>
<sql:maxIdle>8</sql:maxIdle>
<sql:minIdle>0</sql:minIdle>
<sql:maxWait>-1</sql:maxWait>
<sql:timeBetweenEvictionRunsMillis>-1</sql:timeBetweenEvictionRunsMillis>
<sql:metadata>true</sql:metadata>
</jbi:provides>
</jbi:services>
</jbi:jbi>
{code}

h3. Service Unit content

The Service Unit has to contain the following elements, packaged in an archive:
* The META-INF/jbi.xml descriptor file, has described above
{code}
service-unit.zip
+ META-INF
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; - jbi.xml (as defined above)
{code}

h1. Component Configuration
{note}Caution: the component requires at least a JDBC Shared Library. Please install first a valid Shared Library containing your database JDBC driver. Then you can configure your component by using PEtALS maven plugin with the goal jbi:configure or the PEtALS Ant task petals-configure-component.{note}

The following attributes can be set during the installation phase to configure the component, using the params element of the jbi-install-component ANT task:

| acceptor-pool-size | The size of the thread pool used to accept Message Exchanges from the NMR. Once a message is accepted, its processing is delegated to the processor pool thread. | 3 | Yes | Runtime |
| processor-pool-size | The size of the thread pool used to&nbsp;process Message Exchanges. Once a message is accepted, its processing is delegated to one of the thread of this pool. | 10 | Yes | Runtime |
| processor-max-pool-size | The maximum size of the thread pool used to process Message Exchanges. The difference between this size and the processorpool-size represents the dynamic threads that can be created and destroyed during overhead processing time. \\ | 50 | No | Runtime |
| notifications | Enable the EDA mode. The component produces and consumes notifications. See the EDA documentation for further details. \\ | false | No | Installation |
| ignored-status | When the component receives an acknowledgement message exchange, it can skip the processing of these message according to the type of the acknowledgment. If you decide to not ignore some acknowledgement, the component listeners must take care of them. \\
\\
Accepted values : DONE_AND_ERROR_IGNORED, DONE_IGNORED, ERROR_IGNORED or NOTHING_IGNORED | DONE_AND_ERROR_IGNORED | Yes | Component |
| properties-file | Name of the file containing properties used as reference by other parameters. Parameters reference the property name in the following pattern $\{myPropertyName}. At runtime, the expression is replaced by the value of the property. \\
\\
The value of this parameter is :
* an URL
* a file relative to the PEtALS installation path
* an empty value to stipulate a non-using file | \- | No | Installation |
| external-listener-class-name | Qualified name of the class extending *AbstractExternalListener*
{note}Only for Binding Components{note} | \- | No | Component |
| jbi-listener-class-name | Qualified name of the class extending *AbstractJBIListener* | \- | Yes | Component |
{table-plus}
{petalslink}{include:0 CDK Component Configuration Table}{petalslink}

*Definition of CDK parameter scope :*

* *Component :* The parameter has been defined during the development of the component. A user of the component can not change its value.
* *Installation:* The parameter can be set during the installation of the component, by using the installation MBean (see JBI specifications for details about the installation sequence). If the parameter is optional and has not been defined during the development of the component, it is not available at installation time.
* *Runtime :* The paramater can be set during the installation of the component and during runtime. The runtime configuration can be changed using the CDK custom MBean named RuntimeConfiguration. If the parameter is optional and has not been defined during the development of the component, it is not available at installation and runtime times.

{petalslink}{include:0 CDK Parameter scope}{petalslink}

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