Article ID: 825043 - Last Review: November 2, 2007 - Revision: 4.3

FIX: Rows are unexpectedly deleted when you run a distributed query to delete or to update a linked server table

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Bug #: 469673 (SQL Server 8.0)

SYMPTOMS

When you run a distributed query that uses a four-part name to delete or to update rows on a linked server table in a Microsoft SQL Server 2000 database, the rows in the linked server table that do not satisfy the join condition are also deleted. This problem may occur if the DELETE Transact-SQL statement or the UPDATE Transact-SQL statement in the distributed query involves a join and uses non-ANSI syntax. This problem may not occur if you run a distributed query that uses the same instance of SQL Server as the linked server in the distributed query.

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RESOLUTION

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft SQL Server 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

290211 (http://support.microsoft.com/kb/290211/ ) How to obtain the latest SQL Server 2000 service pack

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Hotfix information

The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.

   Date         Time   Version            Size    File name
   ---------------------------------------------------------------------
   31-May-2003  06:15  2000.80.818.0      78,400  Console.exe      
   24-Jun-2003  12:31  2000.80.818.0      33,340  Dbmslpcn.dll     
   24-Apr-2003  13:42                    786,432  Distmdl.ldf
   24-Apr-2003  13:42                  2,359,296  Distmdl.mdf
   29-Jan-2003  13:25                        180  Drop_repl_hotfix.sql
   23-Jun-2003  10:10  2000.80.837.0   1,557,052  Dtsui.dll        
   23-Jun-2003  10:10  2000.80.837.0     639,552  Dtswiz.dll       
   23-Apr-2003  14:21                    747,927  Instdist.sql
   02-May-2003  13:26                      1,581  Inst_repl_hotfix.sql
   07-Feb-2003  18:10  2000.80.765.0      90,692  Msgprox.dll      
   31-Mar-2003  13:37                      1,873  Odsole.sql
   04-Apr-2003  13:16  2000.80.800.0      62,024  Odsole70.dll     
   07-May-2003  08:11  2000.80.819.0      25,144  Opends60.dll     
   02-Apr-2003  09:18  2000.80.796.0      57,904  Osql.exe         
   02-Apr-2003  10:45  2000.80.797.0     279,104  Pfutil80.dll     
   22-May-2003  10:27                     19,195  Qfe469571.sql
   11-Jul-2003  04:34                  1,084,147  Replmerg.sql
   04-Apr-2003  09:23  2000.80.798.0     221,768  Replprov.dll     
   07-Feb-2003  18:10  2000.80.765.0     307,784  Replrec.dll      
   11-Jul-2003  04:26                  1,085,925  Replsys.sql
   31-May-2003  12:31  2000.80.818.0     492,096  Semobj.dll       
   31-May-2003  05:57  2000.80.818.0     172,032  Semobj.rll
   28-May-2003  11:59                    115,944  Sp3_serv_uni.sql
   31-May-2003  12:31  2000.80.818.0   4,215,360  Sqldmo.dll       
   07-Apr-2003  05:14                     25,172  Sqldumper.exe    
   19-Mar-2003  05:50  2000.80.789.0      28,672  Sqlevn70.rll
   01-Jul-2003  11:48  2000.80.834.0     180,736  Sqlmap70.dll     
   07-Feb-2003  18:10  2000.80.765.0      57,920  Sqlrepss.dll     
   21-Jul-2003  07:24  2000.80.842.0   7,553,105  Sqlservr.exe     
   07-Feb-2003  18:10  2000.80.765.0      45,644  Sqlvdi.dll       
   24-Jun-2003  12:31  2000.80.818.0      33,340  Ssmslpcn.dll     
   31-May-2003  12:31  2000.80.818.0      82,492  Ssnetlib.dll     
   31-May-2003  12:31  2000.80.818.0      25,148  Ssnmpn70.dll     
   31-May-2003  12:31  2000.80.818.0     158,240  Svrnetcn.dll     
   31-May-2003  06:29  2000.80.818.0      76,416  Svrnetcn.exe     
   30-Apr-2003  11:22  2000.80.816.0      45,132  Ums.dll          
   01-Jul-2003  11:49  2000.80.834.0      98,816  Xpweb70.dll

Note Because of file dependencies, the most recent hotfix or feature that contains these files may also contain additional files.

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WORKAROUND

To work around this problem, follow these steps:

Create a unique index on the linked server table that the distributed query deletes or updates.
Replace the non-ANSI syntax of the DELETE Transact-SQL statement or of the UPDATE Transact-SQL statement in the distributed query with ANSI syntax.

The following example re-creates the problem condition:

Create a test database on your instance of SQL Server that is to be used as the source server.
Add a computer that is running SQL Server as a linked server to your instance of SQL Server.

On the computer that is running SQL Server and that was added as a linked server, run the following Transact-SQL script to create two tables:

CREATE TABLE ct_batch (
[BAT_PKEY] int NOT NULL ,
[BTYP_KEY] int NOT NULL ,
[BAT_START_DT] datetime NULL,
[BAT_END_DT] datetime NULL,
[BAT_STATUS] varchar(50) NULL,
[BAT_DO_WORK_FLAG] int NULL)

CREATE TABLE ct_batch_element ( 
[BAT_KEY] int NOT NULL ,
[BECC_KEY] int NOT NULL ,
[BE_LINK_KEY] int NOT NULL ,
[BE_CUST_STRING] varchar(20) NULL,
[BE_CUST_VALUE] float NULL)
GO

Run the following Transact-SQL script to populate the test data in the tables that you created in step 3:

DECLARE @count int
SET @count = 0
WHILE @count < 100
BEGIN
INSERT INTO ct_batch VALUES (@count,2,GETDATE(),GETDATE(),'closed',0)
INSERT INTO ct_batch_element VALUES (100,1,@count,null,null)
SET @count = @count + 1
END
INSERT INTO ct_batch VALUES (100,2,GETDATE(),GETDATE(),'current',0)
GO

On the source SQL Server database, run the following Transact-SQL script:

DELETE Linked Server Name.pubs.dbo.ct_batch_element 
FROM Linked Server Name.pubs.dbo.ct_batch_element A 
JOIN Linked Server Name.pubs.dbo.ct_batch B
ON A.bat_key=B.bat_pkey 
WHERE A.be_link_key = 1

Note One hundred rows may be deleted instead of only one row.

To work around the problem that occurs in the previous example, follow these steps:

On the computer that is running SQL Server and that was added as a linked server, run the following Transact-SQL script to repopulate the test data that was deleted:

DECLARE @count int
SET @count = 0
WHILE @count < 100
BEGIN
INSERT INTO ct_batch VALUES (@count,2,GETDATE(),GETDATE(),'closed',0)
INSERT INTO ct_batch_element VALUES (100,1,@count,null,null)
SET @count = @count + 1
END
INSERT INTO ct_batch VALUES (100,2,GETDATE(),GETDATE(),'current',0)
GO

On the computer that is running SQL Server and that was added as a linked server, run the following Transact-SQL script:
CREATE UNIQUE INDEX idx1 ON ct_batch_element(be_link_key)

On the source SQL Server database, run the following Transact-SQL script:

DELETE Linked Server Name.pubs.dbo.ct_batch_element 
FROM Linked Server Name.pubs.dbo.ct_batch_element A
WHERE A.be_link_key = 1 
AND EXISTS ( SELECT * 
	     FROM Linked Server Name.pubs.dbo.ct_batch B 
	     WHERE B.bat_pkey = A.bat_key )

Note Only one row is deleted, as specified in the filter condition in the query.

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STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.This problem was first corrected in Microsoft SQL Server 2000 Service Pack 4.

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