kris

• Mar 14th, 2005

 

The difference between UNION ALL and UNION is that, while UNION only selects distinct values, UNION ALL selects all values.

Nagaraja Rao

• Jun 6th, 2005

 

Union will filter duplicate values where as union all will not filter duplicate values

biswaranjanbehera

 Profile Answers by biswaranjanbehera 

• Jul 25th, 2008

 

in "union" only distinct values will be selected but in "union all "values will be selected irrespective of its frequency.

anil.padharthi

 Profile Answers by anil.padharthi 

• Mar 9th, 2011

 

The difference between UNION ALL and UNION is that, while UNION only selects distinct values, UNION ALL selects all values.
When ever we say union the data type is supposed to be same