MySQL 查询 - 使用 CAST 和 SUM 时组函数无效

Question

我有以下查询生成“无效使用组函数”错误:

SELECT dac_name, unit_name, ptn, unit_type, monthly_recurring, directory_charges
FROM sprint WHERE date='$current_sprint_date' AND CAST( directory_charges AS DECIMAL( 10, 2 ) ) > SUM( CAST( directory_charges AS DECIMAL( 10, 2 ) ) * .01) ORDER BY CAST(directory_charges AS DECIMAL(10,2)) DESC LIMIT 10; 

似乎无法弄清楚。非常感谢任何帮助。

Answer 1

您不能在 WHERE 子句中使用诸如 SUM() 之类的聚合函数。聚合取决于所选的行，因此在选择行时使用它们没有意义。您可以在 HAVING 子句中使用它，该子句在选择并处理行后执行第二个过滤器:

SELECT dac_name, unit_name, ptn, unit_type, monthly_recurring, directory_charges
FROM sprint
WHERE date='$current_sprint_date'
HAVING CAST( directory_charges AS DECIMAL( 10, 2 ) ) > SUM( CAST( directory_charges AS DECIMAL( 10, 2 ) ) * .01)
ORDER BY CAST(directory_charges AS DECIMAL(10,2)) DESC
LIMIT 10;