SQL GROUPBY月

Question

這是我的查詢：

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

我想組appointment_date列按月如下：

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

但我的查詢會引發以下錯誤：

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

Answer 1

這項工作：

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