Set operations allow combining results from multiple SELECT statements. There are four main types: Union combines results and eliminates duplicates. Intersect returns only common records. Union All and Intersect All also show duplicate rows. Syntax involves a SELECT query followed by a set operator and another SELECT query.

1. SET OPERATIONS:
Set operations are used to join the results of two (or more) SELECT statements.
FOUR DIFFERENT TYPES OF SET OPERATIONS:
• Union
• Union all
• Intersect
• Intersect all

2. PREPARED BY
MS. S. NANDHINI -III-B.SC - INFORMATION TECHNOLOGY
UNDER THE GUIDANCE OF
Mrs.P.Anusha M.Sc(IT).,M.Phil.,D.P.T.T.,(Ph.D).,
Assistant professor,
Department of Information Technology,
Bon secours college for women,
Thanjavur.

3. • SQL supports few set operations which can be performed on the tablle
data.
• These are used to get meaningful results from data stored in the table,
under Different special conditions.

4. SYNTAX FOR SET OPERATIONS:
<query1><set operator><query 2>
UNION:
UNION is used to combine the results of two or more SELECT statements. However it will
eliminate duplicate rows from its result set.
In case of union, number of columns and data type must be same in both the tables, on which
UNION operation is being applied.

5. SYNTAX FOR UNION:
• Select column name1, column name 2 from table name1 union select column name1, column
name 2 from table name 2.
EXAMPLE:
Table 1 Table 2 Table1 U table2
UNION ALL:
This operation is similar to union.
but it also shows the duplicate rows.
NAME AGE
Anu 19
seeth
a
20
NAME AGE
Seetha 20
Geetha 21
NAME AGE
Anu 19
Seetha 20
Geetha 21

6. SYNTAX FOR UNION ALL:
• Select column name1,column name2 from tablename1 union all select column
name1, column name2 from tablename2.
INTERSECT:
Intersect operation is used to combine two SELECT statements, but it only returns the records
which are common from both SELECT statements. In case of intersect the number of Columns
and datatype must be same.
NAME AGE
Anu 19
Seetha 20
Seetha 20
Geetha 21

7. SYNTAX FOR INTERSECT:
• Select column name1, column name2 from tablename1 intersect select column name
1,column name 2 from tablename2.
EXAMPLE:
INTERSECT ALL:
It is same as INTERSECT, returns all distinct rows selected
by both queries.
NAME AGE
Seetha 19

8. SYNTAX FOR INTERSECT ALL:
• Select column name1, column name2 from tablename1 intersect all select column
name1, column name2 from tablename 2.
NAME AGE
Seetha 19
Seetha 19

9. MINUS:
The minus operation combines results of two SELECT statements and return only those in the final
result, which belongs to the final set of the result.