Self -Join

Self Join

Self Join this is a regular join, Self Join is used to join a table to itself. There is no keyword for this join.

Syntax :

SELECT  a.column_name b.column_name
FROM table1a,  table1b 
WHERE   a.common_field  = b.common_field;

Example : Figure in below we have customers table. Lets see how to work self Join in database.

Now, let see join this table using SELF JOIN as follows 

Query : 

SELECT  a.Id b.Name, a.Address
FROM customers a,  customers b 
WHERE   a.Address  = b.Address;

Output :