爲什麼我的查詢不起作用？

Question

這是我的查詢：

SELECT [MsgType],sr.ServiceName,content,COUNT(*) AS Occurrence 
FROM [VSReceiveSend].[dbo].[ReceiveBuffer] rb 
    INNER JOIN dbo.Services sr ON rb.ServiceCode=sr.Code 
where MsgType is not null and MsgType = 2 
group by MsgType,CONTEnt, sr.ServiceName 
order by COUNT(*) DESC 

UNION 

SELECT [MsgType],sr.ServiceName,content,COUNT(*) AS Occurrence 
FROM [VSReceiveSend].[dbo].ReceivedSMS rb 
    INNER JOIN dbo.Services sr ON rb.ServiceCode=sr.Code 
where MsgType is not null and MsgType = 2 
group by MsgType,CONTEnt, sr.ServiceName 
order by COUNT(*) DESC 

SQL給我這個錯誤：Incorrect syntax near the keyword 'UNION'！問題是什麼？

Answer 1

一些評論有關查詢：

• 你可能想union all而不是union。如果兩行碰巧具有完全相同的三個字段，我懷疑你想刪除其中的一個。
• 您的where條款是多餘的。

（這是除了order by問題。）

SELECT [MsgType], sr.ServiceName, content, COUNT(*) AS Occurrence 
FROM [VSReceiveSend].[dbo].[ReceiveBuffer] rb INNER JOIN 
    dbo.Services sr 
    ON rb.ServiceCode =s r.Code 
where MsgType = 2 
group by content, sr.ServiceName 
UNION ALL 
SELECT [MsgType], sr.ServiceName, content, COUNT(*) AS Occurrence 
FROM [VSReceiveSend].[dbo].ReceivedSMS rb INNER JOIN 
     dbo.Services sr 
     ON rb.ServiceCode = sr.Code 
where MsgType = 2 
group by MsgType, content, sr.ServiceName 
order by Occurrence DESC; 

注意，這會給你多行。如果你想要一個總數，然後在聚合前做union all：

SELECT MsgType, sr.ServiceName, content, COUNT(*) AS Occurrence 
FROM (select msgtype, servicecode, content 
     from [VSReceiveSend].[dbo].[ReceiveBuffer] rb 
     where MsgType = 2 
     union all 
     select 
     from [VSReceiveSend].[dbo].ReceivedSMS rb 
     where MsgType = 2 
    ) rb INNER JOIN 
    dbo.Services sr 
    ON rb.ServiceCode = sr.Code 
group by MsgType, content, sr.ServiceName 
order by Occurrence DESC; 

Answer 2

UNION關鍵字前面不能有ORDER BY子句。

如果要通過設置以及COUNT（*）記錄命令，你可以添加一列這樣的：

SELECT [MsgType],sr.ServiceName,content,COUNT(*) AS Occurrence, 1 AS recordset_order 
FROM [VSReceiveSend].[dbo].[ReceiveBuffer] rb 
    INNER JOIN dbo.Services sr ON rb.ServiceCode=sr.Code 
where MsgType is not null and MsgType = 2 
group by MsgType,CONTEnt, sr.ServiceName 
UNION 
SELECT [MsgType],sr.ServiceName,content,COUNT(*) AS Occurrence, 2 AS recordset_order 
FROM [VSReceiveSend].[dbo].ReceivedSMS rb 
    INNER JOIN dbo.Services sr ON rb.ServiceCode=sr.Code 
where MsgType is not null and MsgType = 2 
group by MsgType,CONTEnt, sr.ServiceName 
order by recordset_order ASC, COUNT(*) DESC