JDBC escape syntax for outer joins

Derby interprets the JDBC escape syntax for outer joins (and all join operations) as equivalent to the correct SQL syntax for outer joins or the appropriate join operation.

For information about join operations, see JOIN operations.

Syntax

{ oj joinOperation [ joinOperation ]* }

Equivalent to

joinOperation [ joinOperation ]*

Examples

-- outer join
SELECT *
FROM
{oj Countries LEFT OUTER JOIN Cities ON 
   (Countries.country_ISO_code=Cities.country_ISO_code)}
-- another join operation
SELECT *
FROM
{oj Countries JOIN Cities ON (Countries.country_ISO_code=Cities.country_ISO_code)}
-- a tableExpression can be a join operation. Therefore
-- you can have multiple join operations in a FROM clause
SELECT E.EMPNO, E.LASTNAME, M.EMPNO, M.LASTNAME
FROM {oj EMPLOYEE E INNER JOIN DEPARTMENT
INNER JOIN EMPLOYEE M ON MGRNO = M.EMPNO ON E.WORKDEPT = DEPTNO};