SQL GROUPBY月

Question

这是我的查询：

SELECT COUNT(*) AS Expr1, name, appointment_date 
FROM ReportingTable 
GROUP BY name, appointment_date 

我想组appointment_date列按月如下：

SELECT COUNT(*) AS Expr1, name, appointment_date 
FROM ReportingTable 
GROUP BY name, MONTH(appointment_date) 

但我的查询会引发以下错误：

Column "appointment_date" is invalid in the selected list because it is not contained in either aggregate function or groupby clause .

Answer 1

这项工作：

SELECT  COUNT(*) AS Expr1, name, MONTH(appointment_date) AS appointment_month 
FROM   ReportingTable 
GROUP BY name, appointment_month