SQL Server 2012 - 触发器：操作数类型冲突：int与唯一标识符不兼容

Question

我在写一个审计触发器，它将另一个表中发生的每一个变化都保存在表中。但我收到的时候我试图改变Users表这个错误：

操作数类型冲突：int是具有独特标识符

的Users表包含uniqueidentifier列，以及其他不兼容。

这里是哪里发生错误的部分代码：

ALTER TRIGGER [dbo].[UsersLogger] 
ON [dbo].[Users] 
FOR INSERT, DELETE, UPDATE 
AS 
BEGIN 
    DECLARE @audit_oldvalue sql_variant; 
    DECLARE @audit_value sql_variant; 
    DECLARE @audit_field varchar(100); 
    DECLARE @sql nvarchar(max); 
    DECLARE @ParmDefinition nvarchar(max) ; 
    DECLARE @OutString varchar(max) ; 
    DECLARE @converted_uid nvarchar(50); 

    DECLARE @qid int ; 
    DECLARE @Cinfo VARBINARY(128) 

    SELECT @Cinfo = Context_Info() 

    IF @Cinfo = 0x55555 
     RETURN 

    DECLARE @Action as char(1); 
    SET @Action = (CASE WHEN EXISTS(SELECT * FROM INSERTED) 
         AND EXISTS(SELECT * FROM DELETED) 
         THEN 'U' -- Set Action to Updated. 
         ELSE NULL -- Skip. It may have been a "failed delete". 
        END) 

    SET @OutString = '' 

    SELECT * 
    INTO #tempTrigT 
    FROM 
     (SELECT * 
     FROM deleted 
     WHERE @Action IN ('U', 'D')) A 
    UNION 
    (SELECT * 
    FROM inserted 
    WHERE @Action = 'I') 

    SET @sql = '' 

if @Action = 'U' 
BEGIN 
Select @sql = @sql + 'Case when IsNull(i.[' + Column_Name + 
'],0) = IsNull(d.[' + Column_name + '],0) then '''' 
else ' + quotename(Column_Name, char(39)) + ' + '',''' + ' end +' 
from information_schema.columns 
where table_name = 'Users' and column_name <>'rowguid' and column_name <>'modifieddate' 
set @ParmDefinition = '@OutString varchar(max) OUTPUT' 
set @sql = 'Select @OutString = ' 
+ Substring(@sql,1 , len(@sql) -1) + 
' From dbo.Users i ' 
+ ' inner join #tempTrigT d on 
i.id = d.id' 
exec sp_executesql @sql, @ParmDefinition, @OutString OUT 

END 

DECLARE @Items VARCHAR(max) 

set @Items = @OutString; 

DECLARE @Item VARCHAR(50) 
DECLARE @Pos INT 
DECLARE @Loop BIT 
SELECT @Loop = CASE WHEN LEN(@OutString) > 0 THEN 1 ELSE 0 END 
WHILE (SELECT @Loop) = 1 
BEGIN 
SELECT @Pos = CHARINDEX(',', @OutString, 1) 
IF @Pos > 0 
BEGIN 
SELECT @Item = SUBSTRING(@OutString, 1, @Pos - 1) 
SELECT @OutString = SUBSTRING(@OutString, @Pos + 1, LEN(@OutString) - @Pos) 

IF (TRY_CONVERT(UNIQUEIDENTIFIER, @Item) is not null) 
begin 
    select @Item = convert(nvarchar(50), @Item) 
end 

Answer 1

如果我猜的话，我会责怪

Select @sql = @sql + 'Case when IsNull(i.[' + Column_Name + 
'],0) = IsNull(d.[' + Column_name + '],0) then '''' 
else ' + quotename(Column_Name, char(39)) + ' + '',''' + ' end +' 
from information_schema.columns 
where table_name = 'Users' and column_name <>'rowguid' and column_name <>'modifieddate' 

这是因为你在做一个ISNULL在UNIQUEIDENTIIFIER列上并将该值设置为INT。但是，您可以将ISNULL(i.[ColumnName], 0)更改为ISNULL(i.[ColumnName], '')，假设您的表中的所有列都是适用于字符串的数据类型。否则，可以使用该表中的[DATA_TYPE]列，对ISNULL函数的替换值执行一些条件逻辑。