Comments on: SQL SERVER – Introduction and Example of UNION and UNION ALL http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/ Personal Notes of Pinal Dave Sun, 12 Feb 2012 09:22:39 +0000 hourly 1 http://wordpress.com/ By: sagar koti http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-221161 Mon, 19 Dec 2011 08:07:01 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-221161 how to give descriptive headers for each column we pull from the database for the fixed length query.

]]> By: JACOB http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-151046 Wed, 27 Jul 2011 12:56:33 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-151046 Hi Ria,
Did you ever get a solution for this? What alternative did you use?

]]> By: Madhivanan http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-63246 Fri, 19 Mar 2010 08:10:08 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-63246 Also beware of implicit convertions

select 10
union all
select getdate()

]]> By: Brian Tkatch http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-61248 Tue, 16 Feb 2010 13:19:45 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-61248 @navi

please show the query so someone can help you with it.

]]> By: navi http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-61201 Mon, 15 Feb 2010 19:37:52 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-61201 Hi
I have a question .

I need to use select statement and use two from clauses.

that is, everything is same in both the select statements and from clause except there is an extra join in one from clause. what i am trying to do is use condition and take the reqired from clause but i could not do it.

Any help plz

]]> By: Aparna http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-52639 Tue, 02 Jun 2009 07:58:46 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-52639 I was short of time with lots of work in hand so did not really look at the execution plan. I will post my findings in this forum. Thanks Imran for your suggestion. wondering if anyone had similar issues.

FYI Table 1 is not distint by itself and Table 2 is not distinct by itself but there are dateid’s in Table1 and Table2 that makes their union distinct

TABLE1
DATEID INVESTOR
20090530 1
20090530 2
20090530 1

TABLE 2

DATEID INVESTOR
20090630 1
20090630 2
20090630 1

Any one has thoughts until I look at the execution plan

]]> By: Imran Mohammed http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-52631 Tue, 02 Jun 2009 04:59:59 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-52631 @Aparna,

Why don’t you look at Execution plan. Look at cost of each step and each query. You will get an answer.

Also, please post your observation.

~ IM.

]]> By: Aparna http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-52626 Tue, 02 Jun 2009 02:28:42 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-52626 I was looking at performance gaining and a friend of mine doing a peer review of my code suggested that we use union all instead of union, I was not sure how I will gain performance and while researching came across your article.

I do need a distinct list of records and therefore used union
but she has an opinion that I do a union all and then group by the columns individually before applying union all.

Which is best?
get the distinct list of table 1 (by using group by clause) and distinct list of table2 and then do union all

or select list from table 1 and select list from table 2 and do union there by eliminating duplicates in individual tables

]]> By: Ria http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-52534 Fri, 29 May 2009 11:11:55 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-52534 Is it possible to use ‘union all’ in hibernate, Since I am using Java and Hibernate for my application, I need to convert the query using ‘union all’ to hibernate.Please Help me to solve this issue.

]]> By: chris http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-50261 Tue, 31 Mar 2009 06:00:46 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-50261 sorry for the dumb question, i should have included tcol3 in my inner query…

]]> By: chris http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-50260 Tue, 31 Mar 2009 05:55:17 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-50260 is ther a way to use a union all statement and then issue a where at the end to filter the entire query?

example:

table 1
tcol1 tcol2 tcol3
1 1 1
2 2 1

table 2
tcol1 tcol2 tcol3
3 3 1
4 4 2

SELECT tcol1,tcol2 FROM (
SELECT tcol1,tcol2
UNION ALL
SELECT tcol1,tcol2
) AS temptable
WHERE tcol3=’1′ <—

thanks

]]> By: Siuli Basu http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-45222 Wed, 31 Dec 2008 08:43:40 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-45222 I want to know the difference between UNION and INSERT INTO

]]> By: Vani K Patil http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-44151 Tue, 11 Nov 2008 09:34:05 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-44151 First time i am going through this site.It’s simply the best.
U have all the details without redundant details. Thanks tons for this.

]]> By: Joggee http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-43703 Wed, 15 Oct 2008 03:32:05 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-43703 Its a hobby to read your blog’s article on daily basis to refresh my knowledge.

Some tricky part which mostly ignore, Catch it from your articles.

Keep up the good work.

God Bless you

Joggee.

]]> By: Imran Mohammed http://blog.sqlauthority.com/2008/10/15/sql-server-introduction-and-example-of-union-and-union-all/#comment-43701 Wed, 15 Oct 2008 02:04:23 +0000 http://sqlauthority.wordpress.com/?p=1364#comment-43701 Hello,

I wish I had read this article one day before.

Yesterday when I was working on one production issue, I saw a strange case, in which we create two temporary table on the fly, and then we do a select statement with a union. Every time we use to get an error… You wont believe we spent 2-3 hours on it. At last we saw the temporary tables that were created with select * into command was creating different datatype, one with int and another with char, and union was not able to perform its action and our process was failing. I learnt a good lesson, it was worth it :)

Thanks,
Imran.

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