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=",">
(#{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">
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