java MyBatis，插入复杂对象
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MyBatis, insert with complex object
提问by Koop4
I have the following scenario:
我有以下场景：
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:
在我的 Query.xml 上，我以这种方式编写了插入内容：
<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:
阅读 mybatis Result Map Guide 后，我尝试在 mybatis-config.xml 文件中添加以下几行：
<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:
但我不断收到以下错误：
### 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?
谁能澄清我如何设置这个？
采纳答案by AngerClown
The resultMapattribute in <association>needs to refer to the name of your result map, not the Java type: <association property="MyChildObject" resultMap="PrimaryKeyMap"/>
resultMapin的属性<association>需要引用结果映射的名称，而不是 Java 类型：<association property="MyChildObject" resultMap="PrimaryKeyMap"/>
However, if MyChildObjectis 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.
但是，如果MyChildObject作为单独的表存储在数据库中，则不支持嵌套插入。您将需要在 Java 中调用这两个插入。ResultMaps 用于选择。
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:
如果您只是将一张表中的几列放在一个单独的对象中，那么您可以使用点表示法来做到这一点，myChildObject.myField_4. 像这样的东西：
<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>
