摘要:
SQL在线练习 https://h.w.com/lin/h select SUBSTRING_INDEX("https://h.w.com/lin/h", '/', 3) 效果: https://h.w.com huangwanlin SELECT left("huangwanlin" ,5) 效果 阅读全文
摘要:
查询排行及所有(表名.*) 1. set @rownum=0; SELECT @rownum:=@rownum+1 AS top, customer.* FROM customer 2. SELECT @rownum:=@rownum+1 AS top, customer.* FROM (SELEC 阅读全文