'register_composite()' also works with tables

Skip dropped and hidden columns when inspecting the schema.

doc/src/extras.rst

@@ -168,8 +168,9 @@ Composite types casting
 .. versionadded:: 2.4
 
 Using `register_composite()` it is possible to cast a PostgreSQL composite
-type (e.g. created with |CREATE TYPE|_ command) into a Python named tuple, or
+type (either created with the |CREATE TYPE|_ command or implicitly defined
-into a regular tuple if :py:func:`collections.namedtuple` is not found.
+after a table row type) into a Python named tuple, or into a regular tuple if
+:py:func:`collections.namedtuple` is not found.
 
 .. |CREATE TYPE| replace:: :sql:`CREATE TYPE`
 .. _CREATE TYPE: http://www.postgresql.org/docs/9.0/static/sql-createtype.html

lib/extras.py

@@ -913,7 +913,8 @@ SELECT t.oid, %s, attname, atttypid
 FROM pg_type t
 JOIN pg_namespace ns ON typnamespace = ns.oid
 JOIN pg_attribute a ON attrelid = typrelid
-WHERE typname = %%s and nspname = %%s
+WHERE typname = %%s AND nspname = %%s
+    AND attnum > 0 AND NOT attisdropped
 ORDER BY attnum;
 """ % typarray, (tname, schema))
 

tests/test_types_extras.py

@@ -658,6 +658,51 @@ class AdaptTypeTestCase(unittest.TestCase):
         curs.execute("select (1,2)::type_ii")
         self.assertRaises(psycopg2.DataError, curs.fetchone)
 
+    @skip_if_no_composite
+    @skip_before_postgres(8, 4)
+    def test_from_tables(self):
+        curs = self.conn.cursor()
+        curs.execute("""create table ctest1 (
+            id integer primary key,
+            temp int,
+            label varchar
+        );""")
+
+        curs.execute("""alter table ctest1 drop temp;""")
+
+        curs.execute("""create table ctest2 (
+            id serial primary key,
+            label varchar,
+            test_id integer references ctest1(id)
+        );""")
+
+        curs.execute("""insert into ctest1 (id, label) values
+                (1, 'test1'),
+                (2, 'test2');""")
+        curs.execute("""insert into ctest2 (label, test_id) values
+                ('testa', 1),
+                ('testb', 1),
+                ('testc', 2),
+                ('testd', 2);""")
+
+        psycopg2.extras.register_composite("ctest1", curs)
+        psycopg2.extras.register_composite("ctest2", curs)
+
+        curs.execute("""
+            select ctest1, array_agg(ctest2) as test2s
+            from (
+                select ctest1, ctest2
+                from ctest1 inner join ctest2 on ctest1.id = ctest2.test_id
+                order by ctest1.id, ctest2.label
+            ) x group by ctest1;""")
+
+        r = curs.fetchone()
+        self.assertEqual(r[0], (1, 'test1'))
+        self.assertEqual(r[1], [(1, 'testa', 1), (2, 'testb', 1)])
+        r = curs.fetchone()
+        self.assertEqual(r[0], (2, 'test2'))
+        self.assertEqual(r[1], [(3, 'testc', 2), (4, 'testd', 2)])
+
     def _create_type(self, name, fields):
         curs = self.conn.cursor()
         try: