一、行列转换
基本思路：
1. 将数据转转为标书数据，如图所示
2. 使用笛卡尔积做行列转换
select sum(case when childr=‘餐饮‘ then money end ) as ‘餐饮‘ , sum(case when childr=‘通讯‘ then money end ) as ‘通讯‘ , sum(case when childr=‘娱乐‘ then money end ) as ‘娱乐‘ from (select childr, convert(sum(money), decimal(10,2)) as money from wx_spend group by childr) tmp;
一、单列转多行转换
原数据样式
处理后数据样式
SQL语句
CREATE TABLE tmp_sequence (id INT PRIMARY KEY AUTO_INCREMENT); INSERT INTO tmp_sequence VALUES(),(),(),(),(),(),(),(),(),(),(),(),(),(),(),(),(),(),(),(); SELECT name, REPLACE(SUBSTRING(SUBSTRING_INDEX(courseinfo, ‘,‘, a.id), CHAR_LENGTH(SUBSTRING_INDEX(courseinfo, ‘,‘, a.id-1)) + 1), ‘,‘ ,‘‘) AS courseinfo FROM tmp_sequence a CROSS JOIN (SELECT name, concat(courseinfo,",") AS courseinfo, LENGTH(courseinfo) - LENGTH(REPLACE(courseinfo, ‘,‘, ‘‘)) + 1 AS size FROM W_SalesCoursePackageInfo LIMIT 1,1) b ON a.id <= b.size
