Skip to Content
Transact-SQL Desk Reference
book

Transact-SQL Desk Reference

by Deac Lancaster
November 2003
Intermediate to advanced
816 pages
14h 53m
English
Pearson
Content preview from Transact-SQL Desk Reference

4.6. SET OPERATIONS

4.6.1. SET Operations — UNION , UNION ALL

4.6.1.1. UNION Operator

UNION Operator combines the results of two or more queries into a single result set consisting of all the rows belonging to all queries in the union. This is different from using joins that combine columns from two tables.

Two basic rules for combining the result sets of two queries with UNION are as follows.

The number and the order of the columns must be identical in all queries.

The data types must be compatible. See Table 4-8.

Syntax
{< query specification > | ( < query expression > ) }
UNION [ ALL ]
< query specification | ( < query expression > )
[ UNION [ ALL ] < query specification | ( < query expression > )
[ ...n ] ]
Arguments
< query_specification ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Read now

Unlock full access

More than 5,000 organizations count on O’Reilly

AirBnbBlueOriginElectronic ArtsHomeDepotNasdaqRakutenTata Consultancy Services

QuotationMarkO’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.
Julian F.
Head of Cybersecurity
QuotationMarkI wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.
Addison B.
Field Engineer
QuotationMarkI’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.
Amir M.
Data Platform Tech Lead
QuotationMarkI'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Mark W.
Embedded Software Engineer

You might also like

The Real MCTS SQL Server 2008 Exam 70-433 Prep Kit

The Real MCTS SQL Server 2008 Exam 70-433 Prep Kit

Mark Horninger
What Successful Project Managers Do

What Successful Project Managers Do

W. Scott Cameron, Jeffrey S. Russell, Edward J. Hoffman, Alexander Laufer

Publisher Resources

ISBN: 0130293393Purchase book