Support for FULL OUTER JOIN (#162)

Signed-off-by: Balram Choudhary <bchoudhary@rocketsoftware.com>

Author: bchoudhary6415

ibm_db_sa/base.py

@@ -470,11 +470,15 @@ def get_select_precolumns(self, select, **kwargs):
             return ""
 
     def visit_join(self, join, asfrom=False, **kwargs):
-        # NOTE: this is the same method as that used in mysql/base.py
-        # to render INNER JOIN
+        join_type = " INNER JOIN "
+        if join.full:
+            join_type = " FULL OUTER JOIN "
+        elif join.isouter:
+            join_type = " LEFT OUTER JOIN "
+
         return ''.join(
             (self.process(join.left, asfrom=True, **kwargs),
-             (join.isouter and " LEFT OUTER JOIN " or " INNER JOIN "),
+             join_type,
              self.process(join.right, asfrom=True, **kwargs),
              " ON ",
              self.process(join.onclause, **kwargs)))