From b3824aa6cbecc97fc0cd54773417045e69adc87a Mon Sep 17 00:00:00 2001
From: Stefan Rijnhart <stefan@opener.am>
Date: Tue, 12 Jun 2018 09:44:26 +0200
Subject: [PATCH] [RFR] Hide implementation of constraint definition storage,
 courtesy of Raphael Collet

---
 odoo/models.py    |  6 +++---
 odoo/tools/sql.py | 20 ++++++++------------
 2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/odoo/models.py b/odoo/models.py
index 94cbf31a6bc..c4e748ca4d9 100644
--- a/odoo/models.py
+++ b/odoo/models.py
@@ -2445,11 +2445,11 @@ class BaseModel(MetaModel('DummyModel', (object,), {'_register': False})):
 
         def process(key, definition):
             conname = '%s_%s' % (self._table, key)
-            has_definition = tools.constraint_definition(cr, self._table, conname)
-            if not has_definition:
+            current_definition = tools.constraint_definition(cr, self._table, conname)
+            if not current_definition:
                 # constraint does not exists
                 tools.add_constraint(cr, self._table, conname, definition)
-            elif tools.constraint_comment(cr, self._table, conname) != definition:
+            elif current_definition != definition:
                 # constraint exists but its definition may have changed
                 tools.drop_constraint(cr, self._table, conname)
                 tools.add_constraint(cr, self._table, conname, definition)
diff --git a/odoo/tools/sql.py b/odoo/tools/sql.py
index b1c7ecbbf3a..2a0594b7d34 100644
--- a/odoo/tools/sql.py
+++ b/odoo/tools/sql.py
@@ -120,17 +120,13 @@ def drop_not_null(cr, tablename, columnname):
 
 def constraint_definition(cr, tablename, constraintname):
     """ Return the given constraint's definition. """
-    cr.execute('SELECT pg_get_constraintdef(c.oid) FROM pg_constraint c '
-               'JOIN pg_class t ON t.oid = c.conrelid '
-               'WHERE t.relname = %s AND conname=%s', (tablename, constraintname,))
-    return cr.fetchone()[0] if cr.rowcount else None
-
-def constraint_comment(cr, tablename, constraintname):
-    """ Return the given constraint's comment. """
-    cr.execute('SELECT d.description FROM pg_description d '
-               'JOIN pg_constraint c ON c.oid = d.objoid '
-               'JOIN pg_class t ON t.oid = c.conrelid '
-               'WHERE t.relname = %s AND conname = %s;', (tablename, constraintname,))
+    query = """
+        SELECT COALESCE(d.description, pg_get_constraintdef(c.oid))
+        FROM pg_constraint c
+        JOIN pg_class t ON t.oid = c.conrelid
+        LEFT JOIN pg_description d ON c.oid = d.objoid
+        WHERE t.relname = %s AND conname = %s;"""
+    cr.execute(query, (tablename, constraintname))
     return cr.fetchone()[0] if cr.rowcount else None
 
 def add_constraint(cr, tablename, constraintname, definition):
@@ -145,7 +141,7 @@ def add_constraint(cr, tablename, constraintname, definition):
     except Exception:
         msg = "Table %r: unable to add constraint %r!\n" \
               "If you want to have it, you should update the records and execute manually:\n%s"
-        _schema.warning(msg, tablename, constraintname, query, exc_info=True)
+        _schema.warning(msg, tablename, constraintname, query1, exc_info=True)
 
 def drop_constraint(cr, tablename, constraintname):
     """ drop the given constraint. """