在SQL比較兩個變量WHILE循環

Question

我收到錯誤

消息102，級別15，狀態1，行16
附近有語法錯誤@PacketCode「。

當我嘗試執行。我的WHILE循環有些問題，但我看不到。有什麼建議麼？

DECLARE @PacketCode as varchar(255) 
SET @PacketCode = 'ZZZ_Archive_TEST' 

DECLARE @Value as varchar(255) 
SET @Value = '' 

DECLARE @i int 
SET @i = 1 

SELECT 
    @Value = (SELECT packetcode 
       FROM tblScriptReports 
       WHERE packetcode = @PacketCode) 

WHILE (@PacketCode = @Value) 
BEGIN 
    @PacketCode = @PacketCode + ' (' + @i + ')' 

    SELECT @Value = (SELECT packetcode 
        FROM tblScriptReports 
        WHERE packetcode = @PacketCode) 

    SET @i = @i + 1     
END 

SELECT @PacketCode 

Answer 1

嘗試添加一個設置在@PacketCode前在BEGIN：

DECLARE @PacketCode as varchar(255) 
set @PacketCode = 'ZZZ_Archive_TEST' 

DECLARE @Value as varchar(255) 
set @Value = '' 

DECLARE @i int 
set @i = 1 

SELECT @Value = (SELECT packetcode 
      FROM tblScriptReports 
      WHERE packetcode = @PacketCode) 

WHILE (@PacketCode = @Value) 

BEGIN 

SET @PacketCode = @PacketCode + ' (' + @i + ')' 

    SELECT @Value = (SELECT packetcode 
        FROM tblScriptReports 
        WHERE packetcode = @PacketCode) 

    set @i = @i + 1     
END 

select @PacketCode 

Answer 2

在TSQL分配變量值與SET命令。

因此，不是這樣的：

@PacketCode = @PacketCode + ' (' + @i + ')' 

必須這樣做：

SET @PacketCode = @PacketCode + ' (' + @i + ')' 

搞笑的是你的代碼這樣做正確的其他地方。