MyBatis insert操作返回主键

淩亂°似流年 2022-06-14 05:51 197阅读 0赞

在使用MyBatis做持久层时，insert语句默认是不返回记录的主键值，而是返回插入的记录条数；如果业务层需要得到记录的主键时，可以通过配置的方式来完成这个功能

针对Sequence主键而言，在执行insert sql前必须指定一个主键值给要插入的记录，如Oracle、DB2，可以采用如下配置方式：

SELECT SEQ\_TEST.NEXTVAL FROM DUAL

</selectKey>

insert into category (name\_zh, parent\_id,

show\_order, delete\_status, description

)

values (\#\{nameZh,jdbcType=VARCHAR\},

\#\{parentId,jdbcType=SMALLINT\},

\#\{showOrder,jdbcType=SMALLINT\},

\#\{deleteStatus,jdbcType=BIT\},

\#\{description,jdbcType=VARCHAR\}

)

</insert>

针对自增主键的表，在插入时不需要主键，而是在插入过程自动获取一个自增的主键，比如MySQL，可以采用如下两种配置方式：

insert into category (name\_zh, parent\_id,

show\_order, delete\_status, description

)

values (\#\{nameZh,jdbcType=VARCHAR\},

\#\{parentId,jdbcType=SMALLINT\},

\#\{showOrder,jdbcType=SMALLINT\},

\#\{deleteStatus,jdbcType=BIT\},

\#\{description,jdbcType=VARCHAR\}

)

</insert>

或

SELECT LAST\_INSERT\_ID() AS id

</selectKey>

insert into category (name\_zh, parent\_id,

show\_order, delete\_status, description

)

values (\#\{nameZh,jdbcType=VARCHAR\},

\#\{parentId,jdbcType=SMALLINT\},

\#\{showOrder,jdbcType=SMALLINT\},

\#\{deleteStatus,jdbcType=BIT\},

\#\{description,jdbcType=VARCHAR\}

)

</insert>

在插入操作完成之后，参数category的id属性就已经被赋值了

如果数据库表的主键不是自增的类型，那么就需要应用层生成主键的方式··········这个就不多说了，需要的朋友，可以留言交流··

\-----------------------------------------

下面是针对Oracle的写法,Oracle没有autoincrement，而是用触发器实现的 CURRVAL是在触发器中定义的.  
<insert id="insert" parameterClass="ProFeeKindObject">  
      <!\[CDATA\[  
         INSERT INTO t\_pro\_feeKind (KINDID,kindName,kindType,enable)  
         VALUES (seq\_t\_pro\_feekind\_id.nextval,\#kindName\#,\#kindType\#,\#enable\#)  
        \]\]>  
        <selectKey resultClass="java.lang.Integer" keyProperty="kindId" >  
        SELECT seq\_t\_pro\_feekind\_id.CURRVAL AS kindId FROM DUAL  
        </selectKey>      
</insert>  
  
  
  
其他参考代码：  
持久化某个实体对象（如保存一个对象）时，如果我们不用selectKey，那么我们不会立刻得到实体对象的Id属性的，也就是数据表主键  
Java代码  
Permission permission = new Permission();  
permission.set...  
  
permmisonDao.createPermission(permission);  
assertNull(permission);  
Permission permission = new Permission();  
permission.set...

permmisonDao.createPermission(permission);  
assertNull(permission);

selectKey元素与其在父元素中的位置有关

<insert id="addPermission" parameterClass="Permission">     
     <selectKey resultClass="int" keyProperty="permissionId">     
         SELECT SEQ\_P\_PERMISSION.NEXTVAL FROM DUAL      
     </selectKey>     
     INSERT INTO P\_PERMISSION (  
         PERMISSIONID, PERMISSIONINFO, PERMISSIONNAME, PERMISSIONENNAME, URL  
     ) VALUES (  
         \#permissionId\#, \#permissionInfo\#, \#permissionName\#, \#permissionEnName\#, \#url\#  
     )      
</insert>

<insert id="addPermission" parameterClass="Permission">  
<selectKey resultClass="int" keyProperty="permissionId">  
SELECT SEQ\_P\_PERMISSION.NEXTVAL FROM DUAL    
</selectKey>  
INSERT INTO P\_PERMISSION (  
PERMISSIONID, PERMISSIONINFO, PERMISSIONNAME, PERMISSIONENNAME, URL  
) VALUES (  
\#permissionId\#, \#permissionInfo\#, \#permissionName\#, \#permissionEnName\#, \#url\#  
)    
</insert>

Mysql、SQLServer在后  
Xml代码

<insert id="addPermission" parameterClass="Permission">       
INSERT INTO P\_PERMISSION (  
     PERMISSIONID, PERMISSIONINFO, PERMISSIONNAME, PERMISSIONENNAME, URL  
) VALUES (  
     \#permissionId\#, \#permissionInfo\#, \#permissionName\#, \#permiss  
ionEnName\#, \#url\#  
)  
<selectKey resultClass="int" keyProperty="permissionId">     
     SELECT LAST\_INSERT\_ID()      
</selectKey>  
</insert>

<insert id="addPermission" parameterClass="Permission">     
INSERT INTO P\_PERMISSION (  
PERMISSIONID, PERMISSIONINFO, PERMISSIONNAME, PERMISSIONENNAME, URL  
) VALUES (  
\#permissionId\#, \#permissionInfo\#, \#permissionName\#, \#permissionEnName\#, \#url\#  
)  
<selectKey resultClass="int" keyProperty="permissionId">  
SELECT LAST\_INSERT\_ID()    
</selectKey>  
</insert>

像上面这样书写，与selectKey的位置联系得太紧密了，iBatis的sqlMap配置文件的selectKey元素有个type属性，可以指定pre或者post表示前生成还是后生成。  
对于Oracle，表示为  
Xml代码

<insert id="addPermission" parameterClass="Permission">     
    <selectKey resultClass="int" keyProperty="permissionId" type="pre">     
        SELECT SEQ\_P\_PERMISSION.NEXTVAL FROM DUAL      
    </selectKey>     
    INSERT INTO P\_PERMISSION (  
        PERMISSIONID, PERMISSIONINFO, PERMISSIONNAME, PERMISSIONENNAME, URL  
    ) VALUES (  
        \#permissionId\#, \#permissionInfo\#, \#permissionName\#, \#permissionEnName\#, \#url\#  
    )      
</insert>

<insert id="addPermission" parameterClass="Permission">  
<selectKey resultClass="int" keyProperty="permissionId" type="pre">  
SELECT SEQ\_P\_PERMISSION.NEXTVAL FROM DUAL    
</selectKey>  
INSERT INTO P\_PERMISSION (  
PERMISSIONID, PERMISSIONINFO, PERMISSIONNAME, PERMISSIONENNAME, URL  
) VALUES (  
\#permissionId\#, \#permissionInfo\#, \#permissionName\#, \#permissionEnName\#, \#url\#  
)    
</insert>

Mysql、SQLServer等表示为：  
Xml代码

<insert id="addPermission" parameterClass="Permission">     
     <selectKey resultClass="int" keyProperty="permissionId" type="post">     
         SELECT LAST\_INSERT\_ID()  
     </selectKey>     
     INSERT INTO P\_PERMISSION (  
         PERMISSIONID, PERMISSIONINFO, PERMISSIONNAME, PERMISSIONENNAME, URL  
     ) VALUES (  
         \#permissionId\#, \#permissionInfo\#, \#permissionName\#, \#permissionEnName\#, \#url\#  
     )      
</insert>

转自：http://289972458.iteye.com/blog/1001851

http://hi.baidu.com/zim\_it/blog/item/8a2bd11205f5b56ecb80c4b7.html