源：https://code.google.com/p/mybatis/wiki/DocUpgrade3
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Conversion Tool
There is a tool available in the downloads section that will help you to convert your iBATIS 2.x sqlmap files into MyBatis 3.x xml mapper files.
Get it from http://mybatis.googlecode.com/files/ibatis2mybatis.zip
The tool is designed around an xslt transformation and some text replacements packaged in an ant task and tries to deliver a good starting point before the more complex work begins.
New DTDs
New sqlMapConfig.xml DTD:
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
New sqlMap (*.map.xml) DTD:
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
Configuration
Root configuration tag <sqlMapConfig> is now <configuration>
Settings
Within the root configuration tag:
<settings x="y" foo="bar"/>
is now:
<settings>
<setting name="x" value="y"/>
<setting name="foo" value="bar"/>
</settings>
and
<settings useStatementNamespaces="true"/>
can be removed, since the use of namespaces has become mandatory.
<typeAlias>
<typeAlias> must be moved out of the <sqlMap> element to <configuration><typeAliases></typeAliases></configuration>
<configuration>
<settings>
...
</settings>
<typeAliases>
<typeAlias ... />
</typeAliases>
</configuration>
<transactionManager> and <dataSource>
<transactionManager type="JDBC" commitRequired="false">
<dataSource type="your.package.CustomDataSourceFactory" />
</transactionManager>
is now:
<environments default="env">
<environment id="env">
<transactionManager type="JDBC">
<property name="commitRequired" value="false"/>
</transactionManager>
<dataSource type="your.package.CustomDataSourceFactory" />
</environment>
</environments>
<sqlMap>
<sqlMap resource=... />
<sqlMap resource=... />
<sqlMap resource=... />
is now:
<mappers>
<mapper resource=... />
</mappers>
Mapping
The root element <sqlMap> is now <mapper>
The attribute parameterClass should be changed to parameterType
The attribute resultClass should be changed to resultType
The attribute class should be changed to type
the columnIndex attribute does not exist anymore for the <result> tag
The groupBy attribute has been eliminated. Here is an example of groupBy from a 2.x sqlMap:
<resultMap id="productRM" class="product" groupBy="id">
<result property="id" column="product_id"/>
<result property="name" column="product_name"/>
<result property="category" column="product_category"/>
<result property="subProducts" resultMap="Products.subProductsRM"/>
</resultMap>
New:
<resultMap id="productRM" type="product" >
<id property="id" column="product "/>
<result property="name " column="product_name "/>
<result property="category " column="product_category "/>
<collection property="subProducts" resultMap="Products.subProductsRM"/>
</resultMap>
Nested resultMaps
These should now be specified using the <association> tag.
<resultMap ...>
<result property="client" resultMap="Client.clientRM"/>
...
</resultMap>
is now:
<resultMap ...>
<association property="client" resultMap="Client.clientRM"/>
...
</resultMap>
<parameterMap>
Although this tag is deprecated, it can be used as in iBatis 2. However for versions up to 3.0.3 there is a bug when using type="map" and not specifying javaType for a parameter. This will result in
There is no getter for property named '...' in 'interface java.util.Map'
This should be solved in MyBatis 3.0.4. For versions 3.0.3 and earlier the workaround is to explicitly specify javaType.
Inline parameters
#value#
is now:
#{value}
jdbcType changes
jdbcType="ORACLECURSOR"
is now:
jdbcType="CURSOR"
and
jdbcType="NUMBER"
is now:
jdbcType="NUMERIC"
Stored procedures
the <procedure> tag doesn't exist anymore. Use <select>, <insert> or <update>.
<procedure id="getValues" parameterMap="getValuesPM">
{ ? = call pkgExample.getValues(p_id => ?) }
</procedure>
is now:
<select id="getValues" parameterMap="getValuesPM" statementType="CALLABLE">
{ ? = call pkgExample.getValues(p_id => ?)}
</select>
If you're calling an insert procedure that returns a value, you can use <select> instead of <insert>, but make sure to specify useCache="false" and flushCache="true". You'll also have to force a commit.
for stored procedures that return a cursor, there is a bug (see issue 30 ) when using nested result maps (i.e. the output parameter's resultMap contains an <association> tag with the resultMap attribute). As long as the issue is not fixed, you have to specify the resultMap of the output parameter on the statement itself as well, or the nested resultMap will not be populated.
Caching
<cacheModel id="myCache" type="LRU">
<flushInterval hours="24"/>
<property name="size" value="100" />
</cacheModel>
is now:
<cache flushInterval="86400000" eviction="LRU"/>
Note: you can omit eviction="LRU" since it is the default.
the <flushOnExecute> tag is replaced by the flushCache attribute for the statements and the cache will be used by all select statements by default.
Dynamic SQL
The most common dynamic SQL in my project is isNotNull. Here is an example replacement regex:
Pattern:
<isNotNull.*?property=\"(.*?)\">
</isNotNull>
Replacement:
<if test="$1 != null">
</if>
Also common is the use of isEqual, you can replace this by a similar <if> tag.
