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Updated on 2022-07-29 GMT+08:00
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OUTER JOIN

This section describes the migration syntax of Oracle OUTER JOIN. The migration syntax determines how the keywords/features are migrated.

An OUTER JOIN returns all rows that meet the join condition. If rows of a table cannot join any rows in the other table, the statement returns these rows. In Oracle:

  • Left outer join of tables A and B returns all rows from A and rows that satisfy the join condition by applying the outer join operator (+) to all columns of B in the WHERE conditions.
  • Right outer join of tables A and B returns all rows from B and rows that satisfy the join condition by applying the outer join operator (+) to all columns of A in the WHERE condition.

GaussDB(DWS) does not support the + operator. The function of this operator is enabled using LEFT OUTER JOIN and RIGHT OUTER JOIN keywords.

Figure 1 Input: OUTER JOIN
Figure 2 Output: OUTER JOIN
Parent topic: Oracle Syntax Migration