如何在引用調用方中正確的sys.objects表的另一個數據庫中創建UDF或View？

Question

使用SQL Server 2008，我想創建一個UDF，它爲我提供了一個對象的創建日期。這是代碼：

create function dbo.GetObjCreateDate(@objName sysname) returns datetime as 
begin 
    declare @result datetime 
    select @result = create_date from sys.objects where name = @objname 
    return @result 
end 
go 

我希望把這個UDF在主數據庫或其他一些共享的數據庫，以便它是從任何地方訪問，但如果我這樣做，則sys.objects參考從拉master數據庫而不是我從中啓動我的查詢的數據庫。我知道你可以這樣做，因爲information_schema視圖位於master，只是將調用包裝到本地sys.objects實例，所以我希望有一個簡單的方法可以用我的UDF來完成。

Answer 1

爲什麼不這樣做呢？

1. 創建在創建包含所有從服務器上的每個數據庫中sys.objects的信息的主數據庫的圖的存儲過程。
2. 每當創建一個數據庫執行CREATE，ALTER或DROP語句被炒魷魚一個DDL Trigger。然後觸發器將在步驟＃1中執行存儲過程。這允許視圖自動更新。
3. （可選）創建一個用戶定義的函數，該函數查詢給定對象的創建日期的視圖。

存儲過程DDL：

USE [master]; 
GO 

CREATE PROCEDURE dbo.BuildAllServerObjectsView 
AS 

SET NOCOUNT ON; 

IF OBJECT_ID('master.dbo.AllServerObjects') IS NOT NULL 
    EXEC master..sp_SQLExec 'DROP VIEW dbo.AllServerObjects;'; 

IF OBJECT_ID('tempdb..Databases') IS NOT NULL 
    DROP TABLE #Databases; 

DECLARE @CreateView varchar(8000); 
SET @CreateView = 'CREATE VIEW dbo.AllServerObjects AS' + CHAR(13)+CHAR(10) + CHAR(13)+CHAR(10); 

SELECT name COLLATE SQL_Latin1_General_CP1_CI_AS AS 'name' 
    INTO #Databases 
    FROM sys.databases 
ORDER BY name; 

DECLARE @DatabaseName nvarchar(100); 
WHILE (SELECT COUNT(*) FROM #Databases) > 0 
BEGIN 
    SET @DatabaseName = (SELECT TOP 1 name FROM #Databases ORDER BY name); 
    SET @CreateView +='SELECT N'+QUOTENAME(@DatabaseName, '''')+' AS ''database_name''' + CHAR(13)+CHAR(10) 
        + '  ,name COLLATE SQL_Latin1_General_CP1_CI_AS AS ''object_name''' + CHAR(13)+CHAR(10) 
        + '  ,object_id' + CHAR(13)+CHAR(10) 
        + '  ,principal_id' + CHAR(13)+CHAR(10) 
        + '  ,schema_id' + CHAR(13)+CHAR(10) 
        + '  ,parent_object_id' + CHAR(13)+CHAR(10) 
        + '  ,type' + CHAR(13)+CHAR(10) 
        + '  ,type_desc' + CHAR(13)+CHAR(10) 
        + '  ,create_date' + CHAR(13)+CHAR(10) 
        + '  ,modify_date' + CHAR(13)+CHAR(10) 
        + '  ,is_ms_shipped' + CHAR(13)+CHAR(10) 
        + '  ,is_published' + CHAR(13)+CHAR(10) 
        + '  ,is_schema_published' + CHAR(13)+CHAR(10) 
        + ' FROM ' + QUOTENAME(@DatabaseName) + '.sys.objects'; 
    IF (SELECT COUNT(*) FROM #Databases) > 1 
     SET @CreateView += CHAR(13)+CHAR(10) + CHAR(13)+CHAR(10) + ' UNION' + CHAR(13)+CHAR(10); 
    ELSE 
     SET @CreateView += ';'; 

    DELETE #Databases 
    WHERE name = @DatabaseName; 
END; 

--PRINT @CreateView --<== Uncomment this to see the DDL for the view. 

EXEC master..sp_SQLExec @CreateView; 

IF OBJECT_ID('tempdb..Databases') IS NOT NULL 
    DROP TABLE #Databases; 

GO 

功能DDL：

USE [master]; 
GO 

CREATE FUNCTION dbo.GetObjCreateDate(@DatabaseName sysname, @objName sysname) RETURNS DATETIME AS 
BEGIN 
    DECLARE @result datetime; 

    SELECT @result = create_date 
     FROM master.dbo.AllServerObjects 
    WHERE [database_name] = @DatabaseName 
     AND [object_name] = @objname; 

    RETURN @result; 
END 
GO 

用法示例：

SELECT master.dbo.GetObjCreateDate('MyDatabase', 'SomeObject') AS 'Created'; 
SELECT master.dbo.GetObjCreateDate(DB_NAME(), 'spt_monitor') AS 'Created'; 

Answer 2

好像有一個未公開的存儲過程，使您可以創建自己的系統對象：sp_ms_marksystemobject

你可以閱讀更多的http://www.mssqltips.com/tip.asp?tip=1612

Answer 3

它有沒有成爲一個功能？如果你只是想訪問它無處不在，一招是把你的代碼在一個varchar和sp_executesql的那樣：

create procedure dbo.GetObjCreateDate(@objName sysname) 
as 
    declare @sql nvarchar(max) 
    select @sql = 'select create_date from sys.objects where name = ''' + @objname + '''' 
    EXEC sp_executesql @sql 
go 

Answer 4

Jaeell幾乎擁有了。試試這個：

CREATE FUNCTION dbo.GetObjCreateDate(@objName sysname, @dbName sysname) 
RETURNS datetime AS 
BEGIN 
    DECLARE @createDate datetime; 
    DECLARE @params nvarchar(50); 
    DECLARE @sql nvarchar(500); 

    SET @params = '@createDate datetime OUTPUT'; 

    SELECT @sql = 'SELECT @createDate = create_date FROM ' + @dbName + '.sys.objects WHERE name = ''' + @objname + ''''; 

    EXEC sp_executesql @sql, @params, @createDate = @createDate OUTPUT;   

    RETURN @createDate 
END 
; 

Answer 5

看看How to Write Your Own System Functions。我相信它可以幫助你