Here I am describing below the Oracle 12c join conditions and join types that allow you to create more advance queries. There are two types of join conditions, which are based on the operator and three types of join types.
- Equijoins: uses the equality operator in queries.
- Non-equijoins: uses the operator Between, Like and so on, instead of equality operator e.g. <, >, =.
- Inner joins: returns a row only when the fields in the join contain values that matches the join condition. Means if values are not equal of join columns then row isn't returned.
- Outer joins: returns a row even when one of the fields in the join condition contains a null value.
- Self joins: returns a row joined on the same table.