sql 计数
场景：统计数据的SQL例证
统计数据的SQL例子
统计数据的SQL例子
/* Formatted on 2011/06/08 17:58 (Formatter Plus v4.8.8) */
SELECT
(SELECT 1 + 1 FROM DUAL) + (SELECT 2 + 2 FROM DUAL) col1,
3 + 4 col2,
34 col3
FROM DUAL;
/* result
COL1 COL2 COL3
---------- ---------- ----------
6 7 34
1 row selected.
*/