mysql数据库命令
sql语句书写顺序为 S.... F.....W ....G...H...O(即:select from where group by having order by )
sql执行顺序为: F..W...G...H...S...O即from where groupby having select orderby
sql语句书写顺序为 S.... F.....W ....G...H...O(即:select from where group by having order by )
sql执行顺序为: F..W...G...H...S...O即from where groupby having select orderby