Mybatis 框架 7

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1.批量更新

<!--nvl(comm,0)如果为 null取0--><update id = "updateEmps">    update emp set comm = (nvl(comm,0) + #{addComm}) where empno in    <foreach collection = "empons" item = "empno" open="(" separator="," close=")">#{empnos}</foreach></update>

//接口 public int updateEmps (Map<String,Object> params);

//用map传值Map<String,Object> params = new HashMap<String,Object>();params.put("addcomm","10");//增加量params.put("empnos",new Integer[]{7839,7788,7360});//传入要修改的id

2.动态更新

<update id = "updateEmpDynamic" parameterType="com.nue.model.Emp">update emp    <set>        <if test-"ename !=null and ename !='' ">            ename = #{ename},        </if>        <if test-"job != null and jab !='' ">            job = #{job},        </if>    </set>    where empno = #{empno}</update>

3.sql片段

通过Sql代码片段，实现sql代码重用
查询用户信息和分页总记录数的代码重用

//mapper.xml文件内<sql id="query_user">    <if test-"ename !=null and ename !='' ">            ename = #{ename},        </if>        <if test-"job != null and jab !='' ">            job = #{job},        </if></sql><update id = "updateEmpDynamic" parameterType="com.nue.model.Emp">update emp    <set>        <include refid="query_user"/>    </set>    where empno = #{empno}</update><select id = "findUserList" parameterType="user" resultType="java.util.Map">select id,username,birthday,address from t_user    <where>        <include refid="query_user"/>    </where></select>

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