oracle - 查询Oracle时出错：不是单组分组函数

Question

我有一个关于Oracle的查询：

SELECT count(*),SUM(price) as total_price,
  (SELECT count(*) as total_card_success FROM Card_trans WHERE status = 4)
FROM Card_trans;

执行时显示错误：

ORA-00937: not a single-group group function
00937. 00000 -  "not a single-group group function"

如何解决这个问题。谢谢

Answer 1

如果您只想计算行数status = 4

SELECT count(*),
       SUM(price) as total_price,
       SUM(CASE WHEN status = 4 
                THEN 1
                ELSE 0
            END) some_alias
  FROM Card_trans;