sql: drop and create views in a single transaction (#6247)

wcs/sql.py

@@ -337,8 +337,7 @@ def do_formdef_tables(formdef, rebuild_views=False):
     if rebuild_views or len(existing_fields - needed_fields):
         # views may have been dropped when dropping columns, so we recreate
         # them even if not asked to.
-        drop_views(formdef)
-        do_views(formdef)
+        redo_views(formdef)
 
     if not 'concerned_roles_array' in existing_fields:
         return ['rebuild_security']
@@ -406,9 +405,21 @@ def do_user_table():
     cur.close()
 
 @guard_postgres
-def drop_views(formdef=None):
-    conn, cur = get_connection_and_cursor()
+def redo_views(formdef):
+    if get_publisher().get_site_option('postgresql_views') == 'false':
+        return
 
+    if formdef.id is None:
+        return
+
+    conn, cur = get_connection_and_cursor()
+    drop_views(formdef, conn, cur)
+    do_views(formdef, conn, cur)
+    conn.commit()
+    cur.close()
+
+@guard_postgres
+def drop_views(formdef, conn, cur):
     # remove the global views
     cur.execute('''SELECT table_name FROM information_schema.views
                    WHERE table_name LIKE %s''', ('wcs\_category\_%',))
@@ -442,20 +453,8 @@ def drop_views(formdef=None):
     for view_name in view_names:
         cur.execute('''DROP VIEW IF EXISTS %s''' % view_name)
 
-    conn.commit()
-    cur.close()
-
-
 @guard_postgres
-def do_views(formdef):
-    if get_publisher().get_site_option('postgresql_views') == 'false':
-        return
-
-    if formdef.id is None:
-        return
-
-    conn, cur = get_connection_and_cursor()
-
+def do_views(formdef, conn, cur):
     # create new view
     table_name = get_formdef_table_name(formdef)
     view_name = 'wcs_view_%s_%s' % (formdef.id,
@@ -524,9 +523,6 @@ def do_views(formdef):
         cur.execute('''CREATE VIEW wcs_category_%s AS SELECT * from wcs_all_forms
                         WHERE category_id = %s''' % (name, category.id))
 
-    conn.commit()
-    cur.close()
-
 
 class SqlMixin(object):
     _table_name = None