The document discusses different types of joins in SQL including inner joins, outer joins, equi joins, and self joins. Inner joins return rows that match between tables, outer joins return all rows including non-matches, and equi joins join tables on equality of columns. Examples are provided to demonstrate left, right, full, and self outer joins as well as equi joins on the same table.

1. Joins
1. It is used to join multiple tables as one table.
2. In SQL Server 8 to 10 tables are joined.
3. Joints are used to join the columns of different tables.
Types of joints:
Inner join:
If the table contains matched records or related records the inner joints can be used
Ex: Equi Join, Self Join
Outer Join:
If the tables are not having match the records or related records then outer joins are used
Ex: Left Outer Join, Right Outer Join, Full Outer Join
Equi Join:
The tables can be joined by using equals to symbol(=)
Ex:
Create Database PacticeDB
GO
Create Table DEPARTMENT
Go
Insert into DEPARTMENT values(DEPTNO int,DNAME varchar(15),LOC varchar(15))
GO
insert DEPARTMENT values(10,”Sales”,”HYD”),
(20,”Accounting”,”HYD”)
GO
Create Table EMPDET
Go
Insert into EMPDET values(ENO int,ENAME varchar(15),SAL varchar(MAX)) ,DEPTNO int)

2. GO
insert DEPARTMENT values(1001,”Ram”,9000,10),
(1002,”Vinod”,8000,10),
(1003,”Ajay”,9200,20),
(1004,”Kiran”,12000,10)
GO
Query:
Select ENO,ENAME ,SAL,DEPARTMENT,DEPTNO,DNAME,LOC
From
DEPARTMENT,EMPDET
Where DEPARTMENT,DEPTNO=EMPDET.DEPTNO
NOTE:
1. EQUI JOIN can be called as natural join. In select statement if where condition is not given then it
is called cross join or Cartesian join
2. It is join record in the 1st table will join with records in the 2nd table. For joining the table column
names can be same or can be different but the values in the columns should be same.
Self join:
If different columns in the table contain similar value then self-join can be used. Self-join means a
table can be joined by itself.
QUERY:
To get subordinate and managers list from Employee table
SELECT D.ENO,D.ENAME,D.JOB,E.ENO,E.ENAME,E.JOB
FROM
EMPLOYEE D,EMPLOYEE E
WHERE E.ENO=D.MGR
OUTER JOINTS
LEFTOUTER JOIN:
It will takes all the records from the first table and will joins with the second table

3. QUERY(Same TABLE Of EQUI JOIN I USED HERE ALSO)
SELECT ENO,ENAME,SAL,DEPARTMENT.DEPTNO,DNAME,LOC FROM
DEPARTMENT.LEFTOUTERJOIN
EMPDET ON DEPARTMENT.DEPTNO=EMPDET.DEPTNO
Full Outer JOIN:
1.It is the combination of left outer join and right outer join
2.It will show all the records from the table
Ex:
Create Database PacticeDB
GO
Create Table EINFO1
Go
Insert into EINFO1 values(ENO int,ENAME varchar(15))
GO
insert EINFO1 values(101,”AJAY”), (102,”RAM”), (103,”KIRAN”), (104,”VIKAS”),
(105,”VIJAY”)
Create Table EINFO2
Go
Insert into EINFO2 values(ENO int,SAL varchar(MAX))
GO
insert EINFO2 values(101,9000), (103,12000),(105,8000)
GO
Create Table EINFO1
Go
Insert into EINFO3 values(ENO int,ENAME varchar(15))
GO
insert EINFO3 values(101,”VIJAY”), (103,”RAM”), (105,”KIRAN”)
GO

4. Create Table EINFO4
Go
Insert into EINFO4 values(ENO int,SAL varchar(MAX))
GO
insert EINFO4 values(101,8000), (102,9000), (103,18000), (104,9000),
(105,8000)
QUERY USING FULL OUTER JOIN):
SELECT A.ENO,A.ENAME,B.SAL
FROM EINFO1 A FULLOUTERJOIN EINFO2 B
ON A.ENO=B.ENO
SELECT D.ENO,C.ENAME,D.SAL
FROM EINFO3 C FULLOUTERJOIN EINFO4 D
ON C.ENO=D.ENO ORDER BY D.ENO
QUERY USING RIGHT OUTER JOIN
SELECT EINFO4.ENO,ENAME,SAL
FROM EINFO3 RIGHTOUTERJOIN EINFO4
ON EINFO3.ENO=EINFO4.ENO
QUERY USING EQUI JOIN(SAME TABLE):
SELECT EINFO4.ENO,ENAME,SAL
FROM EINFO3,EINFO4
WHERE EINFO3.ENO=EINFO4.ENO