yonhu123java的博客

行转列方法一：通过CASE WHEN语句SELECT username, max(CASE WHEN subject = '语文' THEN score END) AS `语文`, max(CASE WHEN subject = '数学' THEN score END) AS `数学`, max(CASE WHEN subject = '英语' THEN score END) AS `英语`FROM pivotGROUP BY usernameORDER BY use.

BEGIN#Routine body goes here…declare i int;declare num varchar(2);set i=0;set num = “0”;while i<32 doset num = concat("",i);– IF i < 10 THEN– set num = concat(“0”,i);– END IF;set @sql_drop_table = concat(‘drop TABLE IF EXISTS t_user_’, nu