1.select * from tablename where ... and ... 2.(1)select count(*) as Jia where 等级='甲' /*Jia表示甲*/ (2)select count(*) as Yi where 等级='乙' /*后面以此类推*/ 其它的问题和他们讲的一样。
SELECT SUM(CASE WHEN 条件1 THEN 1 ELSE 0 END), SUM(CASE WHEN 等级 = '甲' THEN 1 ELSE 0 END), SUM(CASE WHEN 等级 = '乙' THEN 1 ELSE 0 END), SUM(CASE WHEN 等级 = '丙' THEN 1 ELSE 0 END), SUM(CASE WHEN 等级 = '丁' THEN 1 ELSE 0 END), SUM(CASE WHEN 性别 = '男' THEN 1 ELSE 0 END), SUM(CASE WHEN 性别 = '女' THEN 1 ELSE 0 END) FROM YourTable
2.(1)select count(*) as Jia where 等级='甲' /*Jia表示甲*/
(2)select count(*) as Yi where 等级='乙' /*后面以此类推*/
其它的问题和他们讲的一样。
SUM(CASE WHEN 等级 = '乙' THEN 1 ELSE 0 END),
SUM(CASE WHEN 等级 = '丙' THEN 1 ELSE 0 END),
SUM(CASE WHEN 等级 = '丁' THEN 1 ELSE 0 END), SUM(CASE WHEN 性别 = '男' THEN 1 ELSE 0 END),
SUM(CASE WHEN 性别 = '女' THEN 1 ELSE 0 END)
FROM YourTable