Joins concept

Joins:

In ax 4 types of joins is there:

1) Inner join : Select the record from Main Table that have matching record form child table. These two records together and gives single record.

2) Outer join : select all records from Main Table and select the related records from child table. If there is no match ,it gives empty value

3)Exist join : select the records from Main table if there is any records matching in child table. It should return only main table not child table records.

4)Not Exist join : select the records from Main Table if there is no matching records in Child Table. opposite of Exist join.