what is the difference between union and union all
Answer Posted / praveen k. agrawal
union is used For select distinct values from two tables
where as union all is used For select all values including
duplicates from the tables.
For Example Table X contain values(a,b,c) and Table Y
contain values(c,d,e)
In Case Of Union we will get Result-a,b,c,d,e
and other hand (Union All ) we will get-a,b,c,c,d,e.
Is This Answer Correct ? | 23 Yes | 0 No |
Post New Answer View All Answers
Is pl sql different from sql?
Is there any restriction on the use of union in embedded sql?
What is rank function in sql?
What is benefit of creating memory optimized table?
how can we destroy the session, how can we unset the variable of a session? : Sql dba
What are sql injection vulnerabilities?
What is t sql used for?
What is clustered index sql?
What trigger means?
Is foreign key mandatory?
In a distributed database system, can we execute two queries simultaneously?
what is not null constraint? : Sql dba
How do I order by ascending in sql?
What are the events on which a database trigger can be based?
Show how functions and procedures are called in a pl/sql block.