Joins: Joins are used to retrieve the data from multiple tables.
We can join maximum of 256 tables.
Types of Joins:
Inner Join: It is default join type. Result set will contain only matching rows from tables.
Outer Join:
Outer Join can be classified into 3 types.
They are
Left Outer Join:
Incase of Left outer join result set will contain all the rows from left table and only matching rows from right table.
Right Outer Join:
Incase of Right outer join result set will contain all the rows from Right table and only matching rows from Left table.
Full Join:
Result set will contain all the rows from Right Table and all the rows from left table.
Cross Join:
A join with out any condition. Every row in first table with every row in Second table.
Difference between Full outer Join and Cross join:
Full outer join requires condition but Cross join does not required any condition.
We can join maximum of 256 tables.
Types of Joins:
- Inner Join
- Outer Join
- Cross Join
Inner Join: It is default join type. Result set will contain only matching rows from tables.
Outer Join:
Outer Join can be classified into 3 types.
They are
- Left Outer Join
- Right Outer Join
- Full join
Left Outer Join:
Incase of Left outer join result set will contain all the rows from left table and only matching rows from right table.
Right Outer Join:
Incase of Right outer join result set will contain all the rows from Right table and only matching rows from Left table.
Full Join:
Result set will contain all the rows from Right Table and all the rows from left table.
Cross Join:
A join with out any condition. Every row in first table with every row in Second table.
Difference between Full outer Join and Cross join:
Full outer join requires condition but Cross join does not required any condition.
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