Can Anyone explain why NULL is used in this query?

Posted by Rishabh Ohri on Stack Overflow See other posts from Stack Overflow or by Rishabh Ohri
Published on 2010-03-24T10:54:37Z Indexed on 2010/03/24 11:03 UTC
Read the original article Hit count: 320

Filed under:

sql

Also what will be the scenarios where this query is used

select * from TableA where exists  
    (select null from TableB where TableB.Col1=TableA.Col1)

Related posts about sql

SQL SERVER – Concat Strings in SQL Server using T-SQL – SQL in Sixty Seconds #035 – Video

as seen on SQL Authority - Search for 'SQL Authority'
Concatenating string is one of the most common tasks in SQL Server and every developer has to come across it. We have to concat the string when we have to see the display full name of the person by first name and last name. In this video we will see various methods to concatenate the strings. SQL… >>> More
SQL SERVER – Concat Function in SQL Server – SQL Concatenation

as seen on SQL Authority - Search for 'SQL Authority'
Earlier this week, I was delivering Advanced BI training on the subject of “SQL Server 2008 R2″. I had great time delivering the session. During the session, we talked about SQL Server 2010 Denali. Suddenly one of the attendees suggested his displeasure for the product. He said, even though… >>> More
Error with SQL Server Setup 2012 on Windows 2012

as seen on Server Fault - Search for 'Server Fault'
I am trying to install SQL Server on Windows 2012. I was able to finally get the wizard up and running after making some changes on the server, but now it fails no matter what I do with the following error: TITLE: SQL Server Setup failure. SQL Server Setup has encountered the following error: … >>> More
Nested SQL Select statement fails on SQL Server 2000, ok on SQL Server 2005

as seen on Stack Overflow - Search for 'Stack Overflow'
Here is the query: INSERT INTO @TempTable SELECT UserID, Name, Address1 = (SELECT TOP 1 [Address] FROM (SELECT TOP 1 [Address] FROM [UserAddress] ua INNER JOIN UserAddressOrder uo ON ua.UserID = uo.UserID WHERE ua.UserID = u.UserID ORDER BY uo.AddressOrder ASC) q ORDER BY AddressOrder… >>> More
How can I detect which version of SQL (eg SQL 2008 or SQL Azure)

as seen on Stack Overflow - Search for 'Stack Overflow'
I need to detect which version of SQL I am dealing with to perorm various tasks, I need specifically detect if I am on SQL 2008 or SQL Azure. How can I do this with detection code written in SQL? >>> More

Developer IT

Can Anyone explain why NULL is used in this query? - Developer IT

Can Anyone explain why NULL is used in this query?

sql

Related posts about sql

SQL SERVER – Concat Strings in SQL Server using T-SQL – SQL in Sixty Seconds #035 – Video

SQL SERVER – Concat Function in SQL Server – SQL Concatenation

Error with SQL Server Setup 2012 on Windows 2012

Nested SQL Select statement fails on SQL Server 2000, ok on SQL Server 2005

How can I detect which version of SQL (eg SQL 2008 or SQL Azure)

Categories cloud