Syntax
The JOIN SQL language feature is defined in ANSI/ISO SQL92. The language syntax of ANSI JOIN that Ingres has adopted is as follows:
SELECT … FROM source join_type JOIN source ON search_condition
or
SELECT … FROM source join_type JOIN source USING (column {, column})
INNER JOIN and CROSS JOIN are implemented in gateways similarly to OUTER JOIN:
SELECT … FROM source CROSS JOIN source
For complete information about syntax, usage, and examples, see "ANSI/ISO Join Syntax" and "OUTER JOINs" in the Ingres OpenSQL Reference Guide.