Join Operators

Joins that match columns on the basis of equality are called equijoins.

Equijoins use the following comparison operators:

Operator

Meaning

=

Equal to

>

Greater than

>=

Greater than or equal to

<

Less than

<=

Less than or equal to

!=

Not equal to

!>

Less than or equal to

!<

Greater than or equal to

Joins that use the relational operators are collectively called theta joins.

These set of join operators are used for outer joins:

Operator

Action

*=

Include in the results all the rows from the first table, not just the ones where the joined columns match.

=*

Include in the results all the rows from the second table, not just the ones where the joined columns match.

Related concepts
Equijoins and Natural Joins