标签：span pre when 批量更新 multi 批量处理 end name font
mybatis中批量处理更新
1.在jdbc连接URL加上&allowMultiQueries=true, 支持批量操作
jdbc:mysql://192.168.99.100:3306/migu_cms?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT&allowMultiQueries=true
2. 批量更新
（1）使用foreach这样，一条记录update一次，性能比较差，容易造成阻塞
<update id="updateSortBatch" parameterType="java.util.List"> <foreach collection="list" item="banner"> update t_banner_record set sort_id = #{banner.sortId} where id=#{banner.id} </foreach> </update>
（2）使用case when实现
实际的sql格式
UPDATE course SET name = CASE id WHEN 1 THEN ‘name1‘ WHEN 2 THEN ‘name2‘ WHEN 3 THEN ‘name3‘ END, title = CASE id WHEN 1 THEN ‘New Title 1‘ WHEN 2 THEN ‘New Title 2‘ WHEN 3 THEN ‘New Title 3‘ END WHERE id IN (1,2,3)
<update id="updateSortBatch" parameterType="java.util.List"> update t_banner_record <trim prefix="set" suffixOverrides=","> <trim prefix="sort_id=case" suffix="end,"> <foreach collection="list" item="banner" index="index"> when id=#{banner.id} then #{banner.sortId} </foreach> </trim> </trim> where id in <foreach collection="list" item="banner" index="index" separator="," open="(" close=")"> #{banner.id} </foreach> </update>
标签：span pre when 批量更新 multi 批量处理 end name font
原文地址：https://www.cnblogs.com/t96fxi/p/13086496.html
