Added multi part schema name support. Closes #594 and #1341.

3 files changed, 41 insertions, 12 deletions

diff --git a/lib/sqlalchemy/databases/mssql.py b/lib/sqlalchemy/databases/mssql.py
index 03cf73eee..396e8dd24 100644
--- a/lib/sqlalchemy/databases/mssql.py
+++ b/lib/sqlalchemy/databases/mssql.py
@@ -1733,6 +1733,11 @@ class MSSQLIdentifierPreparer(compiler.IdentifierPreparer):
         #TODO: determine MSSQL's escaping rules
         return value
 
+    def quote_schema(self, schema, force=True):
+        """Prepare a quoted table and schema name."""
+        result = '.'.join([self.quote(x, force) for x in schema.split('.')])
+        return result
+
 dialect = MSSQLDialect
 dialect.statement_compiler = MSSQLCompiler
 dialect.schemagenerator = MSSQLSchemaGenerator
diff --git a/lib/sqlalchemy/schema.py b/lib/sqlalchemy/schema.py
index fd99d2de7..47c01024c 100644
--- a/lib/sqlalchemy/schema.py
+++ b/lib/sqlalchemy/schema.py
@@ -881,17 +881,33 @@ class ForeignKey(SchemaItem):
                 raise exc.ArgumentError(
                     "Parent column '%s' does not descend from a "
                     "table-attached Column" % str(self.parent))
-            m = re.match(r"^(.+?)(?:\.(.+?))?(?:\.(.+?))?$", self._colspec,
-                         re.UNICODE)
+
+            m = self._colspec.split('.')
+
             if m is None:
                 raise exc.ArgumentError(
                     "Invalid foreign key column specification: %s" %
                     self._colspec)
-            if m.group(3) is None:
-                (tname, colname) = m.group(1, 2)
-                schema = None
+
+            # A FK between column 'bar' and table 'foo' can be
+            # specified as 'foo', 'foo.bar', 'dbo.foo.bar',
+            # 'otherdb.dbo.foo.bar'. Once we have the column name and
+            # the table name, treat everything else as the schema
+            # name. Some databases (e.g. Sybase) support
+            # inter-database foreign keys. See tickets#1341 and --
+            # indirectly related -- Ticket #594. This assumes that '.'
+            # will never appear *within* any component of the FK.
+
+            (schema, tname, colname) = (None, None, None)
+            if (len(m) == 1):
+                tname   = m.pop()
             else:
-                (schema, tname, colname) = m.group(1, 2, 3)
+                colname = m.pop()
+                tname   = m.pop()
+
+            if (len(m) > 0):
+                schema = '.'.join(m)
+
             if _get_table_key(tname, schema) not in parenttable.metadata:
                 raise exc.NoReferencedTableError(
                     "Could not find table '%s' with which to generate a "
diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index 5042959b2..84b0ff628 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -292,7 +292,7 @@ class DefaultCompiler(engine.Compiled):
             return name
         else:
             if column.table.schema:
-                schema_prefix = self.preparer.quote(column.table.schema, column.table.quote_schema) + '.'
+                schema_prefix = self.preparer.quote_schema(column.table.schema, column.table.quote_schema) + '.'
             else:
                 schema_prefix = ''
             tablename = column.table.name
@@ -613,7 +613,7 @@ class DefaultCompiler(engine.Compiled):
     def visit_table(self, table, asfrom=False, **kwargs):
         if asfrom:
             if getattr(table, "schema", None):
-                return self.preparer.quote(table.schema, table.quote_schema) + "." + self.preparer.quote(table.name, table.quote)
+                return self.preparer.quote_schema(table.schema, table.quote_schema) + "." + self.preparer.quote(table.name, table.quote)
             else:
                 return self.preparer.quote(table.name, table.quote)
         else:
@@ -1094,7 +1094,15 @@ class IdentifierPreparer(object):
                 or self.illegal_initial_characters.match(value[0])
                 or not self.legal_characters.match(unicode(value))
                 or (lc_value != value))
-    
+
+    def quote_schema(self, schema, force):
+        """Quote a schema.
+
+        Subclasses should override this to provide database-dependent 
+        quoting behavior.
+        """
+        return self.quote(schema, force)
+
     def quote(self, ident, force):
         if force is None:
             if ident in self._strings:
@@ -1113,7 +1121,7 @@ class IdentifierPreparer(object):
     def format_sequence(self, sequence, use_schema=True):
         name = self.quote(sequence.name, sequence.quote)
         if not self.omit_schema and use_schema and sequence.schema is not None:
-            name = self.quote(sequence.schema, sequence.quote) + "." + name
+            name = self.quote_schema(sequence.schema, sequence.quote) + "." + name
         return name
 
     def format_label(self, label, name=None):
@@ -1135,7 +1143,7 @@ class IdentifierPreparer(object):
             name = table.name
         result = self.quote(name, table.quote)
         if not self.omit_schema and use_schema and getattr(table, "schema", None):
-            result = self.quote(table.schema, table.quote_schema) + "." + result
+            result = self.quote_schema(table.schema, table.quote_schema) + "." + result
         return result
 
     def format_column(self, column, use_table=False, name=None, table_name=None):
@@ -1163,7 +1171,7 @@ class IdentifierPreparer(object):
         # a longer sequence.
 
         if not self.omit_schema and use_schema and getattr(table, 'schema', None):
-            return (self.quote(table.schema, table.quote_schema),
+            return (self.quote_schema(table.schema, table.quote_schema),
                     self.format_table(table, use_schema=False))
         else:
             return (self.format_table(table, use_schema=False), )