What is the main difference between a UNION statement and a UNION ALL statemen

What is the main difference between a UNION statement and a
UNION ALL statement?

1. A UNION statement eliminates duplicate rows; a UNION
ALL statement includes duplicate rows.
2. A UNION statement can be used to combine any number of
queries; a UNION ALL statement can be used to combine a
maximum of two queries.
3. A UNION statement can only combine queries that have
parallel fields in the SELECT list; a UNION ALL statement
can combine queries with differing SELECT list structures.
4. A UNION statement cannot be used with aggregate
functions; a UNION ALL statement can be used with aggregate
functions.
5. There is no difference between the two statements; they
are interchangeable.

Question Posted / suresh

2 Answers
7639 Views
Saman Bank, Sonata, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

What is the main difference between a UNION statement and a UNION ALL statement? 1. A UNI..

Answer / anil_abbireddy

1. A UNION statement eliminates duplicate rows; a UNION ALL
statement includes duplicate rows.

Is This Answer Correct ?

11 Yes

0 No

What is the main difference between a UNION statement and a UNION ALL statement? 1. A UNI..

Answer / menan

A UNION statement eliminates duplicate rows; a UNION
ALL statement includes duplicate rows.

Is This Answer Correct ?

4 Yes

0 No

Post New Answer