FIX: Server Side Cursor May Return Incorrect Results (286788)

SYMPTOMS

A dynamic or keyset-driven, server side cursor may return incorrect results if all the following conditions are met:

The query uses a Sub-SELECT statement as a column list.
The Sub-SELECT uses the COUNT(*) function.
The Sub-SELECT has an ANSI Join with a condition.
The outer FROM-clause table has a Transact-SQL join with a Sub-SELECT.

RESOLUTION

SQL Server 2000

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

290211 INF: How to Obtain the Latest SQL Server 2000 Service Pack

SQL Server 7.0

To resolve this problem, obtain the latest service pack for Microsoft SQL Server 7.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

301511 INF: How to Obtain the Latest SQL Server 7.0 Service Pack

STATUS

Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

SQL Server 2000
This problem was first corrected in SQL Server 2000 Service Pack 1.

SQL Server 7.0
This problem was first corrected in Microsoft SQL Server 7.0 Service Pack 4.

MORE INFORMATION

To reproduce the problem, run this code:

CREATE TABLE  TABLE1( T1COL1 int NOT NULL PRIMARY KEY)
go
CREATE TABLE  TABLE2(
 T2COL1 int NOT NULL PRIMARY KEY,
 T2COL2 int NOT NULL )
go

CREATE TABLE TABLE3(
	T3COL1 int NOT NULL)
go
Insert into TABLE1(T1COL1) values(4)
Insert into TABLE1(T1COL1) values(3)
Insert into TABLE2(T2COL1, T2COL2) values(5, 3)
Insert into TABLE2(T2COL1, T2COL2) values(6, 4)
Insert into TABLE3(T3COL1) values(6)
go

-------------- REPRO SCRIPT (Correct result would be 0,1) -------------
declare test cursor keyset for Select (select count(*)
      from dbo.TABLE2 as T2 join dbo.TABLE3 as T3 on T3.T3COL1 = T2.T2COL1
      where T2.T2COL2 = T1.T1COL1) as Para
 from dbo.TABLE1 as T1
open test
fetch test
fetch test
deallocate test


--------------- Workaround (Join condition moved to WHERE clause) ----------------
declare test cursor keyset local for Select (select count(*)
      from dbo.TABLE2 as T2, dbo.TABLE3 as T3 
      where T2.T2COL2 = T1.T1COL1 and T3.T3COL1 = T2.T2COL1) as Para
       from dbo.TABLE1 as T1

open test
fetch test
fetch test
deallocate test