SQL server supports following types of joins to retrieve the data from more than one table.
Inner join: This join is used to retrieve the data which are matched into both tables. For example, if table1 have 10 records and table2 have 8 records and only 3 records are matched with each other using condition then only 3 records will return.
Left outer join: This join is used when need to retrieve all data from the left side table and matched data from right side table. For example table1 have 10 records and table2 have 8 records and only 3 records are matched according to condition then left outer join returns 10 records.
Right outer join: This join is used when need to retrieve all data from the right side table and matched data from left side table. For example table1 have 10 records and table2 have 8 records and only 3 records are matched according to condition then right outer join returns 8 records.
Self-join: When we use same table on both side of join then it is called self-join.
Cross join: This join is used to retrieve the cross joined data. Means every record in table1 will join with all the records of table2. For example, If table1 have 10 records and table2 have 8 records then this join will return 80 records.
- Inner join
- Left outer join
- Right outer join
- Self-join
- Cross join
Inner join: This join is used to retrieve the data which are matched into both tables. For example, if table1 have 10 records and table2 have 8 records and only 3 records are matched with each other using condition then only 3 records will return.
Left outer join: This join is used when need to retrieve all data from the left side table and matched data from right side table. For example table1 have 10 records and table2 have 8 records and only 3 records are matched according to condition then left outer join returns 10 records.
Right outer join: This join is used when need to retrieve all data from the right side table and matched data from left side table. For example table1 have 10 records and table2 have 8 records and only 3 records are matched according to condition then right outer join returns 8 records.
Self-join: When we use same table on both side of join then it is called self-join.
Cross join: This join is used to retrieve the cross joined data. Means every record in table1 will join with all the records of table2. For example, If table1 have 10 records and table2 have 8 records then this join will return 80 records.
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