mysql - mysql 中的 IF 和 SUM

Question

我有一个表，它有一个金额和备注字段。如果备注不为0.00，则查询得到金额的SUM，否则获取备注。但我的查询只是将备注添加到查询的总和中。抱歉我的英语不好。

这是我的表格的结构:

amount    |    remarks     |    received    |    request
-------------------------------------------------------------
100.00    |    0.00        |    2016-01-01  |    Completed
100.00    |    0.00        |    2016-01-01  |    Completed
100.00    |    0.00        |    2016-01-01  |    Completed
100.00    |    500.00      |    2016-01-01  |    Completed

我的查询是:

SELECT if (remarks = 0.00, SUM(amount), SUM(remarks)) as AMT , received AS YY, request FROM tbldonation
WHERE request = 'Completed'

结果应该是 800.00，但我的结果是 900.00，它会加上 100 和备注值。

Answer 1

试试这个:

SELECT SUM(IF(remarks = 0.00, amount, remarks)) AS AMT, 
       received AS YY, 
       request 
FROM tbldonation
WHERE request = 'Completed'