From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 2 May 2006 21:30:41 +0000 (+0000)
Subject: gambit's patch to add DISTINCT ON
X-Git-Tag: rel_0_1_7~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5b02351a2e6a80dbd894c8ffacf64d1373d4d9d;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

gambit's patch to add DISTINCT ON
---

diff --git a/lib/sqlalchemy/databases/postgres.py b/lib/sqlalchemy/databases/postgres.py
index 19a703c0ce..a92cb340db 100644
--- a/lib/sqlalchemy/databases/postgres.py
+++ b/lib/sqlalchemy/databases/postgres.py
@@ -309,6 +309,20 @@ class PGCompiler(ansisql.ANSICompiler):
             text += " OFFSET " + str(select.offset)
         return text
 
+    def visit_select_precolumns(self, select):
+        if select.distinct:
+            if type(select.distinct) == bool:
+                return "DISTINCT "
+            if type(select.distinct) == list:
+                dist_set = "DISTINCT ON ("
+                for col in select.distinct:
+                    dist_set += self.strings[col] + ", "
+                    dist_set = dist_set[:-2] + ") "
+                return dist_set
+            return "DISTINCT ON (" + str(select.distinct) + ") "
+        else:
+            return ""
+             
     def binary_operator_string(self, binary):
         if isinstance(binary.type, sqltypes.String) and binary.operator == '+':
             return '||'