|
SELECT store_name,SUM(sales) FROM Store_Information GROUP BY store_name HAVING SUM(salse)>1500 |
SELECT COUNT(store_name) FROM Store_Information WHERE store_name is not NULL |
SELECT store_name FROM Store_Information WHERE Sales>1000 |
|
HAVING是对函数产生的值来设定条件 |
WHERE是对函数的变量来设定条件 |
WHERE给出的是SELECT的条件，即选择栏位的条件，这个条件一般是由某个栏位名来表达、决定 |
原文：http://www.cnblogs.com/nosadness/p/4020787.html