I have the following scenario:
public class MyObj{
private String myField_1
private String myField_2
private MyChildObj myChild
// Constructor & get/set
}
public class MyChildObj{
private String myField_3
private String myField_4
// Constructor & get/set
}
on my Query.xml i wrote the insert in this way:
<insert id="insertMyObj" parameterType="MyObj">
INSERT INTO MY_TABLE ( FIELD_1,
FIELD_2,
FIELD_3,
FIELD_4)
values ( #{myField_1},
#{myField_2},
#{myField_3},
#{myField_4},
)
</insert>
after reading mybatis Result Map Guide i tried to add following lines on mybatis-config.xml file:
<typeAliases>
<typeAlias alias="MyObj" type="myPackage.MyObj"/>
<typeAlias alias="MyChildObj" type="myPackage.MyChildObj"/>
</typeAliases>
<resultMap id="insertObj" type="MyObj">
<result property="myField_1" column="FIELD_1"/>
<result property="myField_2" column="FIELD_2"/>
<association property="PrimaryKeyMap" resultMap="PrimaryKey"/>
</resultMap>
<resultMap id="PrimaryKeyMap" type="PrimaryKey">
<result property=myField_3 column="FIELD_3"/>
<result property="myField_4" column="FIELD_4"/>
</resultMap>
but i keep getting the following error:
### Cause: org.apache.ibatis.builder.BuilderException: Error creating document instance. Cause: org.xml.sax.SAXParseException; lineNumber: xx; columnNumber: xx; Element type "resultMap" must be declared.
Can anyone clarify me how to set up this?
Answer
The resultMap attribute in <association> needs to refer to the name of your result map, not the Java type: <association property="MyChildObject" resultMap="PrimaryKeyMap"/>
However, if MyChildObject is stored in the database as a separate table, nested inserts are not supported. You will need to call both inserts in Java. ResultMaps are for selects.
If you are just putting a few columns from one table in a separate object, then you can do this with dot notation, myChildObject.myField_4. Something like this:
<insert id="insertMyObj" parameterType="MyObj">
INSERT INTO MY_TABLE ( FIELD_1,
FIELD_2,
FIELD_3,
FIELD_4)
values ( #{myField_1},
#{myField_2},
#{myChildObject.myField_3},
#{myChildObject.myField_4},
)
</insert>