MyBatis中的批量插入、删除(MySql、Oracle)

批量插入
批量插入mysql和oracle的sql会有些差别，要注意！

mysql：

<insert id="batchInsert" parameterType="java.util.List">
       insert into user(username, password) values
       <foreach collection="list" item="item" index="index"           separator=",">
           separator=",">
           (#{item.username},
           #{item.password} )
       </foreach>
   </insert>

oracle：

 <insert id="batchInsert" parameterType="java.util.List">
    insert into user(username, password) 
    <foreach close=")" collection="list" item="item" index="index" open="(" separator="union">
        select
        #{item.username,jdbcType=VARCHAR},
        #{item.password,jdbcType=VARCHAR}
        from dual
    </foreach>
</insert>

下面的是Oracle使用 Sequence来生成主键的批量插入写法

<insert id="batchInsert" parameterType="java.util.List">
    insert into user(id, username, password)
       select SEQ_USER_ID.NEXTVAL,T.* from(
       <foreach collection="list" item="item" index="index"           separator="UNION">
           separator="UNION">
           SELECT
        	  #{item.username,jdbcType=VARCHAR},
     		  #{item.password,jdbcType=VARCHAR}
           from dual 
            </foreach>
       ) T
</insert>

批量删除

<delete id="batchDeleteByIdList" parameterType="java.util.List">
    delete from user
    where id in
	<foreach item="id" collection="list" open="(" separator="," close=")">
	#{id}
	</foreach>
  </delete>

当然，也可以使用Array来替代List，修改parameterType=“array”和collection=”array”即可