Supported Join operators

The OpenAccess SDK SQL engine supports the following join operations:

• Implicit JOIN. The WHERE clause explicitly specifies the join condition

• INNER JOIN. All joins that are not OUTER JOINS are considered in SQL terminology as INNER joins. The use of keyword INNER has no additional effects, but helps the statement to be completely self-documenting.

  SELECT * FROM t1 INNER JOIN t2 ON t1.c1 = t2.c3

  WHERE search-condition

• LEFT OUTER JOIN

  SELECT * FROM t1 LEFT OUTER JOIN t2 ON t1.c1 = t2.c3

  WHERE search-condition

• UNION and UNION ALL operators. UNION is used for combining two result tables that are union compatible.

  SELECT c1, c2 FROM t1 UNION SELECT c3, c4 FROM t2