Previous:
Alter Table Statement
Joins are used to retrieve data from two or more tables with relevant conditions which uses the primary key for the table for referencing. Join operation takes two tables as input and return another table as output. When ever we perform a JOIN, we must specify one column that is common in both the tables that are participating in the JOIN. Here we can use multiple joins in the same SQL statement to query data from as many tables as we like to join.
The join return rows when there is at least one match i.e. column in the participated tables.
There are 4 types of Joins
1] Inner Join
2] Outer Join
2.1] Left Outer Join
2.2] Right Outer Join
2.3] Full Outer Join
3] Cartesian Join
4] Self Join
