components/camel-mybatis/src/main/docs/mybatis-component.adoc

= MyBatis Component
:doctitle: MyBatis
:shortname: mybatis
:artifactid: camel-mybatis
:description: Performs a query, poll, insert, update or delete in a relational database using MyBatis.
:since: 2.7
:supportlevel: Stable
:tabs-sync-option:
:component-header: Both producer and consumer are supported
//Manually maintained attributes
:camel-spring-boot-name: mybatis

*Since Camel {since}*

*{component-header}*

The MyBatis component allows you to query, poll, insert, update and
delete data in a relational database using http://mybatis.org/[MyBatis].

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-mybatis</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>
----

== URI format

----
mybatis:statementName[?options]
----

Where *statementName* is the statement name in the MyBatis XML mapping
file which maps to the query, insert, update or delete operation you
wish to evaluate.

You can append query options to the URI in the following format,
`?option=value&option=value&...`

This component will by default load the MyBatis SqlMapConfig file from
the root of the classpath with the expected name of
`SqlMapConfig.xml`. +
 If the file is located in another location, you will need to configure
the `configurationUri` option on the `MyBatisComponent` component.


// component-configure options: START

// component-configure options: END

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

// endpoint options: START

// endpoint options: END

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



== Message Body

The response from MyBatis will only be set as the body if it's a
`SELECT` statement. That means, for example, for `INSERT` statements
Camel will not replace the body. This allows you to continue routing and
keep the original body. The response from MyBatis is always stored in
the header with the key `CamelMyBatisResult`.

== Samples

For example if you wish to consume beans from a JMS queue and insert
them into a database you could do the following:

[source,java]
----
from("activemq:queue:newAccount")
  .to("mybatis:insertAccount?statementType=Insert");
----

Notice we have to specify the `statementType`, as we need to instruct
Camel which kind of operation to invoke.

Where *insertAccount* is the MyBatis ID in the SQL mapping file:

[source,xml]
----
  <!-- Insert example, using the Account parameter class -->
  <insert id="insertAccount" parameterType="Account">
    insert into ACCOUNT (
      ACC_ID,
      ACC_FIRST_NAME,
      ACC_LAST_NAME,
      ACC_EMAIL
    )
    values (
      #{id}, #{firstName}, #{lastName}, #{emailAddress}
    )
  </insert>
----

== Using StatementType for better control of MyBatis

When routing to an MyBatis endpoint you will want more fine grained
control so you can control whether the SQL statement to be executed is a
`SELECT`, `UPDATE`, `DELETE` or `INSERT` etc. So for instance if we want
to route to an MyBatis endpoint in which the IN body contains parameters
to a `SELECT` statement we can do:

In the code above we can invoke the MyBatis statement
`selectAccountById` and the IN body should contain the account id we
want to retrieve, such as an `Integer` type.

We can do the same for some of the other operations, such as
`SelectList`:

And the same for `UPDATE`, where we can send an `Account` object as the
IN body to MyBatis:

=== Using InsertList StatementType

MyBatis allows you to insert multiple rows using its for-each batch
driver. To use this, you need to use the <foreach> in the mapper XML
file. For example as shown below:

Then you can insert multiple rows, by sending a Camel message to the
`mybatis` endpoint which uses the `InsertList` statement type, as shown
below:

=== Using UpdateList StatementType

MyBatis allows you to update multiple rows using its for-each batch
driver. To use this, you need to use the <foreach> in the mapper XML
file. For example as shown below:

[source,xml]
----
<update id="batchUpdateAccount" parameterType="java.util.Map">
    update ACCOUNT set
    ACC_EMAIL = #{emailAddress}
    where
    ACC_ID in
    <foreach item="Account" collection="list" open="(" close=")" separator=",">
        #{Account.id}
    </foreach>
</update>
----

Then you can update multiple rows, by sending a Camel message to the
mybatis endpoint which uses the UpdateList statement type, as shown
below:

[source,java]
----
from("direct:start")
    .to("mybatis:batchUpdateAccount?statementType=UpdateList")
    .to("mock:result");
----

=== Using DeleteList StatementType

MyBatis allows you to delete multiple rows using its for-each batch
driver. To use this, you need to use the <foreach> in the mapper XML
file. For example as shown below:

[source,xml]
----
<delete id="batchDeleteAccountById" parameterType="java.util.List">
    delete from ACCOUNT
    where
    ACC_ID in
    <foreach item="AccountID" collection="list" open="(" close=")" separator=",">
        #{AccountID}
    </foreach>
</delete>
----

Then you can delete multiple rows, by sending a Camel message to the
mybatis endpoint which uses the DeleteList statement type, as shown
below:

[source,java]
----
from("direct:start")
    .to("mybatis:batchDeleteAccount?statementType=DeleteList")
    .to("mock:result");
----

=== Notice on InsertList, UpdateList and DeleteList StatementTypes

Parameter of any type (List, Map, etc.) can be passed to mybatis and an
end user is responsible for handling it as required +
 with the help of http://www.mybatis.org/mybatis-3/dynamic-sql.html[mybatis
dynamic queries] capabilities.

=== Scheduled polling example

This component supports scheduled polling and can therefore be used as
a Polling Consumer. For example to poll the
database every minute:

[source,java]
----
from("mybatis:selectAllAccounts?delay=60000")
  .to("activemq:queue:allAccounts");
----

See "ScheduledPollConsumer Options"
on Polling Consumer for more options.

Alternatively you can use another mechanism for triggering the scheduled
polls, such as the xref:timer-component.adoc[Timer] or xref:timer-component.adoc[Quartz]
components. In the sample below we poll the database, every 30 seconds
using the xref:timer-component.adoc[Timer] component and send the data to the JMS
queue:

[source,java]
----
from("timer://pollTheDatabase?delay=30000")
  .to("mybatis:selectAllAccounts")
  .to("activemq:queue:allAccounts");
----

And the MyBatis SQL mapping file used:

[source,xml]
----
  <!-- Select with no parameters using the result map for Account class. -->
  <select id="selectAllAccounts" resultMap="AccountResult">
    select * from ACCOUNT
  </select>
----

=== Using onConsume

This component supports executing statements *after* data have been
consumed and processed by Camel. This allows you to do post updates in
the database. Notice all statements must be `UPDATE` statements. Camel
supports executing multiple statements whose names should be separated
by commas.

The route below illustrates we execute the *consumeAccount* statement
data is processed. This allows us to change the status of the row in the
database to processed, so we avoid consuming it twice or more.

And the statements in the sqlmap file:

=== Participating in transactions

Setting up a transaction manager under camel-mybatis can be a little bit
fiddly, as it involves externalising the database configuration outside
the standard MyBatis `SqlMapConfig.xml` file.

The first part requires the setup of a `DataSource`. This is typically a
pool (either DBCP, or c3p0), which needs to be wrapped in a Spring
proxy. This proxy enables non-Spring use of the `DataSource` to
participate in Spring transactions (the MyBatis `SqlSessionFactory` does
just this).

[source,xml]
----
<bean id="dataSource" class="org.springframework.jdbc.datasource.TransactionAwareDataSourceProxy">
    <constructor-arg>
        <bean class="com.mchange.v2.c3p0.ComboPooledDataSource">
            <property name="driverClass" value="org.postgresql.Driver"/>
            <property name="jdbcUrl" value="jdbc:postgresql://localhost:5432/myDatabase"/>
            <property name="user" value="myUser"/>
            <property name="password" value="myPassword"/>
        </bean>
    </constructor-arg>
</bean>
----

This has the additional benefit of enabling the database configuration
to be externalised using property placeholders.

A transaction manager is then configured to manage the outermost
`DataSource`:

[source,xml]
----
<bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
</bean>
----

A http://www.mybatis.org/spring/index.html[mybatis-spring]
http://www.mybatis.org/spring/factorybean.html[`SqlSessionFactoryBean`]
then wraps that same `DataSource`:

[source,xml]
----
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="dataSource" ref="dataSource"/>
    <!-- standard mybatis config file -->
<property name="configLocation" value="/META-INF/SqlMapConfig.xml"/>
    <!-- externalised mappers -->
<property name="mapperLocations" value="classpath*:META-INF/mappers/**/*.xml"/>
</bean>
----

The camel-mybatis component is then configured with that factory:

[source,xml]
----
<bean id="mybatis" class="org.apache.camel.component.mybatis.MyBatisComponent">
    <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
</bean>
----

Finally, a transaction policy is defined
over the top of the transaction manager, which can then be used as
usual:

[source,xml]
----
<bean id="PROPAGATION_REQUIRED" class="org.apache.camel.spring.spi.SpringTransactionPolicy">
    <property name="transactionManager" ref="txManager"/>
    <property name="propagationBehaviorName" value="PROPAGATION_REQUIRED"/>
</bean>

<camelContext id="my-model-context" xmlns="http://camel.apache.org/schema/spring">
    <route id="insertModel">
        <from uri="direct:insert"/>
        <transacted ref="PROPAGATION_REQUIRED"/>
        <to uri="mybatis:myModel.insert?statementType=Insert"/>
    </route>
</camelContext>
----

== MyBatis Spring Boot Starter integration

Spring Boot users can use https://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/[mybatis-spring-boot-starter] artifact provided by the mybatis team

[source,xml]
----
<dependency>
  <groupId>org.mybatis.spring.boot</groupId>
  <artifactId>mybatis-spring-boot-starter</artifactId>
  <version>3.0.1</version>
</dependency>
----

in particular AutoConfigured beans from mybatis-spring-boot-starter can be used as follow:

[source,properties]
----
#application.properties
camel.component.mybatis.sql-session-factory=#sqlSessionFactory
----

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