Sql server 在SQLServer中使用GROUPBY

通过这个查询，我得到了两列不同的值

SELECT DISTINCT 
    Transport.ID, Transport.Address 
FROM  
    Cars 
LEFT JOIN 
    Transport ON Cars.TransportFrom=Transport.ID 
ORDER BY 
    address

现在，我需要再获得一列sum：

SUM(CASE WHEN Active='True' THEN 1 ELSE 0 END) 

但如果我像这样做的话，我会出错

SELECT DISTINCT 
    Transport.ID, Transport.Address, 
    SUM(CASE WHEN Active = 'True' THEN 1 ELSE 0 END)
FROM 
    Cars 
LEFT JOIN 
    Transport ON Cars.TransportFrom = Transport.ID 
ORDER BY 
    address

Msg 8120，第16级，状态1，第1行
列“Transport.ID”在选择列表中无效，因为它未包含在聚合函数或GROUP BY子句中

味精156，第15级，状态1，第5行
关键字“GROUP”附近的语法不正确

Msg 209，16级，状态1，第4行
列名称“ID”不明确

Msg 8120，第16级，状态1，第1行
列“Transport.address”在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中

---

如何正确使用语法？

错误信息很清楚，不是吗

SELECT Transport.ID, Transport.Address, SUM(CASE WHEN Active='True' THEN 1 ELSE 0 END)
FROM Cars 
LEFT JOIN Transport ON Cars.TransportFrom=Transport.ID 
--add all the fields from select clause which are not in an aggregation function
GROUP BY Transport.ID, Transport.Address 
ORDER BY address

---

您需要在

groupby

子句中添加

Transport.Address

。

SELECT 
    Transport.ID, Transport.Address, 
    SUM(CASE WHEN Active = 'True' THEN 1 ELSE 0 END)
FROM 
    Cars 
LEFT JOIN 
    Transport ON Cars.TransportFrom = Transport.ID 
GROUP BY 
    ID
ORDER BY 
    address

SELECT 
    Transport.ID, Transport.Address, 
    SUM(CASE WHEN Active = 'True' THEN 1 ELSE 0 END)
FROM 
    Cars 
LEFT JOIN 
    Transport ON Cars.TransportFrom = Transport.ID 
GROUP BY 
    Transport.ID
ORDER BY 
    address

SELECT Transport.ID, Transport.Address, SUM(CASE WHEN Active='True' THEN 1 ELSE 0 END)
FROM Cars 
LEFT JOIN Transport ON Cars.TransportFrom=Transport.ID 
--add all the fields from select clause which are not in an aggregation function
GROUP BY Transport.ID, Transport.Address 
ORDER BY address