From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Tue, 6 Dec 2011 22:41:19 +0000 (-0500)
Subject: - enable SAVEPOINT support fully, remove warning, [ticket:822].
X-Git-Tag: rel_0_7_4~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58e692d76bbea84667609a4ceb828dcf43571f6e;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- enable SAVEPOINT support fully, remove warning, [ticket:822].
It's not known what the potential "data loss" issues are, tests seem to pass.
---

diff --git a/CHANGES b/CHANGES
index 1f67610667..2c77bb4612 100644
--- a/CHANGES
+++ b/CHANGES
@@ -242,6 +242,11 @@ CHANGES
      scripts.
 
 - mssql
+  - [feature] lifted the restriction on SAVEPOINT
+    for SQL Server.  All tests pass using it,
+    it's not known if there are deeper issues
+    however.   [ticket:822]
+
   - [bug] repaired the with_hint() feature which
     wasn't implemented correctly on MSSQL - 
     usually used for the "WITH (NOLOCK)" hint
diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py
index bc50da5ad6..5443a66cbf 100644
--- a/lib/sqlalchemy/dialects/mssql/base.py
+++ b/lib/sqlalchemy/dialects/mssql/base.py
@@ -854,6 +854,9 @@ class MSSQLCompiler(compiler.SQLCompiler):
         return 'DATEPART("%s", %s)' % \
                         (field, self.process(extract.expr, **kw))
 
+    def visit_savepoint(self, savepoint_stmt):
+        return "SAVE TRANSACTION %s" % self.preparer.format_savepoint(savepoint_stmt)
+
     def visit_rollback_to_savepoint(self, savepoint_stmt):
         return ("ROLLBACK TRANSACTION %s" 
                 % self.preparer.format_savepoint(savepoint_stmt))
@@ -1115,12 +1118,12 @@ class MSDialect(default.DefaultDialect):
         super(MSDialect, self).__init__(**opts)
 
     def do_savepoint(self, connection, name):
-        util.warn("Savepoint support in mssql is experimental and "
-                  "may lead to data loss.")
+        # give the DBAPI a push
         connection.execute("IF @@TRANCOUNT = 0 BEGIN TRANSACTION")
-        connection.execute("SAVE TRANSACTION %s" % name)
+        super(MSDialect, self).do_savepoint(connection, name)
 
     def do_release_savepoint(self, connection, name):
+        # SQL Server does not support RELEASE SAVEPOINT
         pass
 
     def initialize(self, connection):
diff --git a/test/lib/requires.py b/test/lib/requires.py
index 9a117b6b13..65ad0aa8f5 100644
--- a/test/lib/requires.py
+++ b/test/lib/requires.py
@@ -96,6 +96,14 @@ def independent_connections(fn):
                 'SQL Server 2005+ is required for independent connections'),
         )
 
+def updateable_autoincrement_pks(fn):
+    """Target must support UPDATE on autoincrement/integer primary key."""
+    return _chain_decorators_on(
+        fn,
+        no_support('mssql', "IDENTITY cols can't be updated"),
+        no_support('sybase', "IDENTITY cols can't be updated"),
+    )
+
 def isolation_level(fn):
     return _chain_decorators_on(
         fn,
@@ -136,7 +144,6 @@ def savepoints(fn):
     """Target database must support savepoints."""
     return _chain_decorators_on(
         fn,
-        emits_warning_on('mssql', 'Savepoint support in mssql is experimental and may lead to data loss.'),
         no_support('access', 'savepoints not supported'),
         no_support('sqlite', 'savepoints not supported'),
         no_support('sybase', 'savepoints not supported'),
diff --git a/test/orm/test_transaction.py b/test/orm/test_transaction.py
index 2a609c4278..c0d6d7c15f 100644
--- a/test/orm/test_transaction.py
+++ b/test/orm/test_transaction.py
@@ -592,6 +592,7 @@ class AutoCommitTest(TransactionTest):
             []
         )
 
+    @testing.requires.updateable_autoincrement_pks
     def test_accounting_no_select_needed(self):
         """test that flush accounting works on non-expired instances
         when autocommit=True/expire_on_commit=True."""