مارا دنبال کنید :
1
2
3 |
SELECT COUNT (aggregate_expression) FROM tables [WHERE conditions]; |
1
2
3
4
5
6
7
8
9
10
11
12
13 |
SELECT COUNT (supplier_id) FROM suppliers; Result: 3 SELECT COUNT (state) FROM suppliers; Result: 1 SELECT COUNT (DISTINCT department) AS "Unique departments" FROM employees WHERE salary > 55000; |