Mybatis相关知识

批量更新

主键更新

<update id="batchUpdate">
        update ems_item
        <trim prefix="set" suffixOverrides=",">
            <trim prefix="x =case" suffix="end,">
                <foreach collection="lists" item="item" index="index">
                    <if test="item.x !=null">when id=#{item.id} then #{item.x}</if>
                    <if test="item.x == null ">when id=#{item.id} then
                        ems_item.x
                    </if>
                </foreach>
            </trim>
            <trim prefix="y =case" suffix="end,">
                <foreach collection="lists" item="item" index="index">
                    <if test="item.y !=null">when id=#{item.id} then #{item.y}</if>
                    <if test="item.y == null ">when id=#{item.id} then
                        ems_item.y
                    </if>
                </foreach>
            </trim>
        </trim>
        where id in
        <foreach collection="lists" index="index" item="item" separator="," open="(" close=")">
            #{item.id,jdbcType=VARCHAR}
        </foreach>
    </update>

多条件更新

<update id="batchUpdate"  parameterType="java.util.List">
        update emv_user_stationgroup
        <trim prefix="set" suffixOverrides=",">
            is_check =
            <foreach collection="list" item="item" open="case " close=" end,">
                when user_id = #{item.userId} AND group_id = #{item.groupId} then #{item.isCheck}
            </foreach>
        </trim>
        <where>
            <foreach collection="list" item="item" open="( " separator=") or (" close=" )">
                user_id = #{item.userId} AND group_id = #{item.groupId}
            </foreach>
        </where>
    </update>