[Solved] Oracle-Conveting SQL to ANSI SQL

Question

This section is probably causing the problem:

  FROM BOM_CHILDS C
     , XX_MAIN.XX_MAST MAST
     , XX_MAIN.XX_STPO STPO
  WHERE C.MATNR = MAST.MATNR(+)
   AND MAST.STLNR = STPO.STLNR(+)
   AND MAST.STLAN(+) = '1'
   AND MAST.WERKS(+) = C.WERKS
   AND STPO.IDNRK IS NULL

To make this a bit easier, lets rearrange the WHERE clause to order the tables by how they relate:

FROM BOM_CHILDS C
 , XX_MAIN.XX_MAST MAST
 , XX_MAIN.XX_STPO STPO
-- Joining C to MAST
WHERE C.MATNR = MAST.MATNR(+)
  AND C.WERKS = MAST.WERKS(+)
  AND MAST.STLAN(+) = '1'
-- Joining MAST to STPO
  AND MAST.STLNR = STPO.STLNR(+)
  AND STPO.IDNRK IS NULL

We have C joined to MAST using C as the “driver” table and picking up data from MAST where it matches (a left join):

FROM BOM_CHILDS C
LEFT JOIN XX_MAIN.XX_MAST MAST
  ON C.MANTR = MAST.MANTR
 AND C.WERKS = MAST.WERKS
 AND MAST.STLAN = '1'

Then we need to add STPO to the joins:

LEFT JOIN XX_MAIN.XX_STPO STPO
  ON MAST.STLNR = STPO.STLNR
 AND STPO.IDNRK IS NULL

Putting it all together we get:

FROM BOM_CHILDS C
LEFT JOIN XX_MAIN.XX_MAST MAST
  ON C.MANTR = MAST.MANTR
 AND C.WERKS = MAST.WERKS
 AND MAST.STLAN = '1'
LEFT JOIN XX_MAIN.XX_STPO STPO
  ON MAST.STLNR = STPO.STLNR
 AND STPO.IDNRK IS NULL

That said, even though (+) works for left/right/outer joins, Oracle recommends not using it:

Oracle recommends that you use the FROM clause OUTER JOIN syntax rather than the Oracle join operator. Outer join queries that use the Oracle join operator (+) are subject to the following rules and restrictions, which do not apply to the FROM clause OUTER JOIN syntax: …

Accepted Answer