Sql - What the difference between UNION and UNIONALL?

radhika_btech · 23-01-07, 09:41 PM

**sk_kireeti** · 24-01-07, 12:14 AM

similar post....
Explain the UNION operation in SQL .

sampada_m · 04-07-08, 07:03 PM

Quote:

Originally Posted by radhika_btech

Sql - What the difference between UNION and UNIONALL?

sampada_m · 04-07-08, 07:03 PM

Quote:

Originally Posted by radhika_btech

Sql - What the difference between UNION and UNIONALL?

The purpose of the SQL UNION ALL command is to combine the results of two or more queries into a single result set consisting of all the rows belong to all queries in the union.
The main difference between UNION ALL and UNION is that, while UNION only selects distinct values, UNION ALL selects all values (including duplicates).

sampada_m · 04-07-08, 07:04 PM

The purpose of the SQL UNION ALL command is to combine the results of two or more queries into a single result set consisting of all the rows belong to all queries in the union.
The main difference between UNION ALL and UNION is that, while UNION only selects distinct values, UNION ALL selects all values (including duplicates).

23-01-07, 09:41 PM	#1 (permalink)
radhika_btech Senior Member Join Date: Jan 2007 Age: 27 Posts: 283 Thanks: 0 Thanked 2 Times in 2 Posts Thanks: 0 Thanked 2 Times in 2 Posts Rep Power: 4	Sql - What the difference between UNION and UNIONALL? Sql - What the difference between UNION and UNIONALL?

24-01-07, 12:14 AM	#2 (permalink)
sk_kireeti Super Moderator Join Date: Feb 2006 Location: Hyderabad Posts: 2,355 Thanks: 117 Thanked 240 Times in 197 Posts Thanks: 117 Thanked 240 Times in 197 Posts Blog Entries: 4 Rep Power: 51	Re: Sql - What the difference between UNION and UNIONALL? similar post.... Explain the UNION operation in SQL . __________________ Give 1 cup rice to a hungry Indian just by a mouse click. No money, no form filling, no hassle... Click here for the donation.

04-07-08, 07:04 PM	#5 (permalink)
sampada_m Junior Member Join Date: Jul 2007 Posts: 6 Thanks: 0 Thanked 0 Times in 0 Posts Thanks: 0 Thanked 0 Times in 0 Posts Rep Power: 2	Re: Sql - What the difference between UNION and UNIONALL? The purpose of the SQL UNION ALL command is to combine the results of two or more queries into a single result set consisting of all the rows belong to all queries in the union. The main difference between UNION ALL and UNION is that, while UNION only selects distinct values, UNION ALL selects all values (including duplicates).

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