Comments on: SQL SERVER – Union vs. Union All – Which is better for performance?

By: shivendra mani tripathi

shivendra mani tripathi — Wed, 23 Nov 2011 12:39:10 +0000

Thanks dear madhivanan …

By: madhivanan

madhivanan — Wed, 23 Nov 2011 10:45:11 +0000

This will get you to find out duplicates

Select col from table
group by col
having count(*)>!

By: shivendra mani tripathi

shivendra mani tripathi — Tue, 22 Nov 2011 11:12:01 +0000

hello everybody..
please assist me how to get only duplicate records from a table1 into a new table2..

thanks in advance sir..please guide me
Shivendra

By: Dip

Dip — Tue, 25 Oct 2011 10:24:34 +0000

Union:1,2,3,4…

By: madhivanan

madhivanan — Fri, 14 Oct 2011 12:44:20 +0000

You need to post expected result from the above sample data. Also explain the logic

By: Rahul

Rahul — Fri, 14 Oct 2011 06:53:53 +0000

select * from @T1 where i not in (select distinct * from @T2 ) union
select * from @T2 where j not in (select distinct * from @T1 )

By: Rahul

Rahul — Fri, 14 Oct 2011 06:52:23 +0000

we can also do this with

select distinct * from @T1 where i not in (select distinct * from @T2 ) union
select distinct * from @T2 where j not in (select distinct * from @T1 ) order by 1 desc

By: guna

guna — Fri, 14 Oct 2011 06:19:08 +0000

PBillno PurDate Partyname Tax SBillno SalDate Partyname Tax
————————————————————————————————-
1 2011-09-30 Raji 14 1 2011-09-30 Test 0
2 2011-09-30 Testing 55.57 4 2011-10-10 Rajesh 1.60
4 2011-10-10 Kumar 0.00 5 2011-10-10 Guna 29.40
5 2011-10-10 Suji 0.00 6 2011-09-10 Ragu 0.80
—————————————————————————————————

This is My Table …

i Have PurDate Same to SalDate.. If Not Enough Then that SalDate Record Null Row..

How do.. Please Help Me..

By: Krishna

Krishna — Sun, 09 Oct 2011 11:00:37 +0000

Krishna

Today i got different scenario where union is working better than union ALL.
One of the point astonished me while using UNION it is returning results in 20 sec where as it is taking more than 10 min

By: Prabahar C

Prabahar C — Fri, 02 Sep 2011 18:54:51 +0000

Good example for Unions.I have one union with 2 select statements,Does SQL consider it as one statement /2 statements?

By: Craig

Craig — Tue, 09 Aug 2011 17:15:54 +0000

Once again you’ve saved the day for me. Mr. Pinal Dave, you’re columns have taught me more about SQL than ten books on the subject. Thank you!

By: SQL SERVER – Interview Questions and Answers – Frequently Asked Questions – Day 9 of 31 Journey to SQLAuthority

Sat, 09 Jul 2011 01:31:48 +0000

[...] The difference between UNION and UNION ALL is that UNION ALL will not eliminate duplicate rows, instead it just pulls all rows from all the tables fitting your query specifics and combines them into a table. (Read more here) [...]

By: Ismail

Ismail — Sat, 28 May 2011 11:26:05 +0000

I CAN’T BELIEVE THAT USING “UNION ALL” BOOSTED MY QUERY AT A 500 % FASTER THAN “UNION”
THANK YOU VERY MUCH BROTHER.

By: rajivgandhi

rajivgandhi — Fri, 13 May 2011 12:22:37 +0000

can u explain savepoint in sq1 server 2008

By: rajivgandhi

rajivgandhi — Fri, 13 May 2011 12:21:09 +0000

use of savepoint

By: nithin bhaktha

nithin bhaktha — Thu, 28 Apr 2011 10:02:13 +0000

Really good article…Understood the difference between both

By: Imran Mohammed

Imran Mohammed — Sun, 24 Apr 2011 05:52:19 +0000

@manu

That’s a typo, What you understood is right.

~IM.

By: manu

manu — Fri, 22 Apr 2011 14:25:10 +0000

Hi Pinal,

If you have two tables.
First table : 1,2,3,4,5
Second table : 1,2,5,6

for Union All:
1,1,2,2,3,4,5,5,6

but you said 1,2,2,3,4,5,5,6

???

By: Yuvraj Gautam

Yuvraj Gautam — Thu, 17 Mar 2011 06:50:08 +0000

@palkalaiselvan
use bulk insert to insert text file in sql

CREATE TABLE [dbo].[empdata](
[empid] [int] NOT NULL,
[empname] [nvarchar](50) NULL,
[empsalary] [int] NULL
) ON [PRIMARY]

BULK INSERT empdata FROM ‘G:\notepad.txt’ WITH
(
FIELDTERMINATOR = ‘\t’, –Tab
ROWTERMINATOR =’\n’–New Row
)

select * from empdata

By: madhivanan

madhivanan — Fri, 18 Feb 2011 11:09:56 +0000

Use Bulk insert
http://beyondrelational.com/blogs/madhivanan/archive/2010/03/17/bulk-insert-to-table-with-specific-columns.aspx

By: palkalaiselvan

palkalaiselvan — Thu, 17 Feb 2011 01:21:14 +0000

100 palkalai 30000
101 raja 5000
102 kumar 4900
103 murali 21000
104 sugumar 13000
105 gugan 8940
106 gobi 56000
107 dhilip 34000

I have records like this in my notepad or word. how can i insert all those records in SQL. send me the query..

By: palkalaiselvan

palkalaiselvan — Thu, 17 Feb 2011 00:58:35 +0000

Hello sir,
If i have a 1000 records in a pdf or word or notepad format. All my 1000 records having just 3 fields like eno,ename,esalary.
I also created table with same field in SQL 2005. By using only one single query i should insert all my 1000 records into the SQL.
Please send me the query for that.

By: James Collett

James Collett — Wed, 03 Nov 2010 12:37:52 +0000

I must say thanks for this article, which confirms how I *thought* the UNION keyword was working. I feel guilty if I just leech knowledge from this page!

By: LamTang

LamTang — Mon, 04 Oct 2010 09:25:00 +0000

I have two table with a lot of record. Now I want get a view
So
Case 1:
Select …
From table1
where….
UNION
Select…
From table2
where…

Case 2:
Select …
From table1
where….
UNION ALL
Select…
From table2
where…

Case3:
declare @tmpTable table(…)
Go
Insert into @tmpTable sSelect … From table1 where….
Go
Insert into @tmpTable sSelect … From table2 where….
Go
select * from @tmpTable
drop @tmpTable

Please help me! Which case is the best performance?

By: swetha

swetha — Fri, 27 Aug 2010 13:39:03 +0000

this is really good soln