PostgreSQL Inner Join | PostgreSQL Tutorials and Solutions

PostgreSQL Inner Join is also called equi join. Inner join can be performed if two or more tables are having a common column.
Name of the column need not to be same and primary key, foreign key relationship not compulsory.

PostgreSQL Inner Join Syntax

SELECT table1.column1, table2.column2...
FROM table1
INNER JOIN table2
ON table1.common_field = table2.common_field;

PostgreSQL Inner Join Examples:

Tables used for below examples:

emp table:

dept table:

 deptno |   dname    |   loc
--------+------------+----------
     40 | OPERATIONS | BOSTON
     30 | SALES      | CHICAGO
     10 | ACCOUNTING | NEW YORK
     20 | RESEARCH   | DALLAS

1. Display employee details with dept details who’s working location is ‘NEW YORK’.

select e.empno,e.ename,e.sal, d.dname,d.loc from emp e join dept d
 on e.deptno=d.deptno
 where d.loc='NEW YORK';

2. Display the employees whose salary is greater than 2000 and work location is ‘CHICAGO’.

select e.empno,e.ename,e.sal, d.dname,d.loc from emp e join dept d
 on e.deptno=d.deptno
and e.sal>2000
and d.loc='CHICAGO';