Trying to migrate from Oracle to PostgreSQL

Question

SELECT b.SERVICENAME,
       a.PARAMETERNAME,
       a.PARAMETERVALUE
FROM serviceParameter a,
     subscriberService b,
     serviceName c
WHERE a.SUBSCRIBERKEY (+) = 15677889
  AND b.SUBSCRIBERKEY = 15677889
  AND b.SERVICENAME = a.SERVICENAME(+)
  AND c.SERVICENAME = b.SERVICENAME
  AND c.MULTIINSTANCE = '0'
ORDER BY a.SERVICENAME;

How can I migrate the above code to PostgresSQL?

Answer 1

You have to translate it along these lines:

SELECT ...
FROM a, b
WHERE a.x = b.y(+)
  AND a.p = 42
  AND b.q(+) = 'foo';

will become:

SELECT ...
FROM a LEFT OUTER JOIN b
        ON a.x = b.y
           AND b.q = 'foo'
WHERE a.p = 42;

That is:

• The side with the (+) becomes the right side of a LEFT OUTER JOIN (or, equivalently, the left side of a RIGHT OUTER JOIN ).

• All the WHERE conditions that contain a (+) lose that adornment and go into the join condition .

It is easy to translate Oracle's join syntax to standard conforming syntax because the latter is more powerful (and easier to read to boot).