一个很经典的mysql的查询语句面试题
t1
t2:
问:请写出SQL语句得到两个月的业绩,期望得到以下结果,请问SQL语句如何写??
结果图:
SQL:select c.dname, a.yj '一月份',b.yj '二月份' from t1 a INNER JOIN t1 b on a.dep = b.dep INNER JOIN t2 c on a.dep = c.dep where a.mon='一月份' and b.mon='二月份'
t1
t2:
结果图:
SQL:select c.dname, a.yj '一月份',b.yj '二月份' from t1 a INNER JOIN t1 b on a.dep = b.dep INNER JOIN t2 c on a.dep = c.dep where a.mon='一月份' and b.mon='二月份'