摘要： 1.列转行表t_pivot转后效果方法 1 (常用方法 case when)SELECT buydate, SUM(CASE WHEN type = '生活' THEN typecount ELSE 0 END) AS 生活, SUM(CASE WHEN type = '学习' THEN typecount ELSE 0 END) AS 学习, SUM(CASE WHEN type = '动画' THEN typecount ELSE 0 END) AS 动画, SUM(CASE WHEN type = '游戏' THEN typ 阅读全文