Very Computer

by **rick** » Sun, 08 Jun 2003 15:40:10

What are some of the possible scenarios that will generate
incorrect results querying data with T-SQL statements?

Rick

by **John Bel** » Sun, 08 Jun 2003 15:57:02

If you have table or index corruption, your output may be effected. Try
using the DBCC commands to verify your database is not corrupt.

John

Quote:> What are some of the possible scenarios that will generate
> incorrect results querying data with T-SQL statements?

> Rick

by **Dan Guzma** » Sun, 08 Jun 2003 17:45:58

Aside from physical corruption, the other possible cause of incorrect
results is a SQL Server bug. However, it's important to distinguish
between *incorrect* results and *unexpected* results. For example, the
following causes a log of folks grief:

CREATE TABLE Table1
(Table1Data int)
CREATE TABLE Table2
(Table2Data int)
GO

INSERT INTO Table1 VALUES(1)
INSERT INTO Table2 VALUES(2)
GO

SELECT * FROM Table1
WHERE Table1Data NOT IN
(
SELECT Table2Data FROM Table2
)
GO

INSERT INTO Table2 VALUES(NULL)
GO

SELECT * FROM Table1
WHERE Table1Data NOT IN
(
SELECT Table2Data FROM Table2
)
GO

--
Hope this helps.

Dan Guzman
SQL Server MVP

-----------------------
SQL FAQ links (courtesy Neil Pike):

http://www.ntfaq.com/Articles/Index.cfm?DepartmentID=800
http://www.sqlserverfaq.com
http://www.mssqlserver.com/faq
-----------------------

Quote:> What are some of the possible scenarios that will generate
> incorrect results querying data with T-SQL statements?

> Rick

Very Computer

incorrect reports

incorrect reports

incorrect reports

incorrect reports