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 pivot GROUP BY username ORDER BY use.

BEGIN #Routine body goes here… declare i int; declare num varchar(2); set i=0; set num = “0”; while i<32 do set 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