執行SQL Server存儲過程時的語法錯誤

Question

ALTER PROCEDURE dbo.encrypt 
    @columnname NVARCHAR(100), 
    @TblName NVARCHAR(200) 
WITH ENCRYPTION 
AS 
BEGIN 
    SET NOCOUNT ON; 

    DECLARE @encryptcolumn NVARCHAR(200); 
    DECLARE @AlterQuery NVARCHAR(200);
    DECLARE @TblName NVARCHAR(200); 

    OPEN SYMMETRIC KEY Password_Key DECRYPTION BY CERTIFICATE PasswordCertificate;
    SET @encryptcolumn = (@columnname + 'encrypt');

    IF @encryptcolumn IS NOT NULL
        SET @AlterQuery = 'ALTER TABLE ['+@TblName+'] add  ['+@encryptcolumn+'] varbinary(max)null);' 

        EXEC sp_executesql @AlterQuery; 

        UPDATE @TblName 
        SET @encryptcolumn = ENCRYPTBYKEY(KEY_GUID('datamartSymKey'), CONVERT(varbinary, @columnname)) 
    END 
GO

當我嘗試執行此操作時，將引發以下錯誤：

變量名“ @TblName”已經聲明。 變量名稱在查詢批處理或存儲過程中必須唯一。

Answer 1

您收到此錯誤的原因是您已經在過程中傳遞了@tblName 。 您可以通過刪除聲明並將值通過過程調用傳遞來解決此問題。

除此之外，您還必須使用EXEC運行更新查詢，因為表名可能會更改。

ALTER PROCEDURE dbo.encrypt @columnname nvarchar(100), @TblName nvarchar(200) WITH ENCRYPTION AS BEGIN SET NOCOUNT ON; 
    DECLARE @encryptcolumn nvarchar(200); 
    DECLARE @AlterQuery nvarchar(200);

    OPEN SYMMETRIC KEY Password_Key DECRYPTION BY CERTIFICATE PasswordCertificate;
    set @encryptcolumn=(@columnname + 'encrypt');
    if @encryptcolumn is not null 
        SET @AlterQuery='ALTER TABLE ['+@TblName+'] add  ['+@encryptcolumn+'] varbinary(max)null);' 
        exec sp_executesql @AlterQuery; 

        DECLARE @sqlCommand varchar(1000)
        SET @sqlCommand = 'UPDATE ' +@TblName + ' SET ' + @encryptcolumn + ' = ENCRYPTBYKEY(KEY_GUID(''datamartSymKey''),CONVERT(varbinary, ' + @columnname + '))'
        EXEC (@sqlCommand)
    END 
GO