How can I convert full outer joins from a Microsoft SQL Server database to an Oracle database?
There are several ways to express a full outer join within an Oracle database. For example, in the following query the predicate a.col1 (+) = b.col1 (+) is similar to the way Oracle notates a full outer join although this predicate is not currently supported in an Oracle database: select a.col2 acol2, a.col1 acol1, b.col1 bcol1, b.col2 bcol2 from a,b where a.col1 (+) = b.col1 (+); The most efficient way of executing this query is to use a UNION ALL of a left outer join and a right outer join, with an additional predicate, for example: select a.col2 acol2, a.col1 acol1, b.col1 bcol1, b.col2 bcol2 from a,b where a.col1=b.col1(+) union all select a.col2 acol2, a.col1 acol1, b.col1 bcol1, b.col2 bcol2 from a,b where a.col1(+)=b.col1 and a.
