一個很經典的mysql的查詢語句面試題
t1
t2:
問:請寫出SQL語句得到兩個月的業績,期望得到以下結果,請問SQL語句如何寫??
結果圖:
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:
結果圖:
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'