cannot copy ForeignKeyConstraint(schema=None) as _get_colspec interprets None as a default

[Paul Harrington]

This bit me when trying to adapt some SQL Server collections which have a schema to a SQLite database that does not. Here is a workaround which I came up with to allow me to copy a collection of tables.

pjjH

We can't use None as the sentinal value as there are times when we

really do want to zap out the schema part. So use a value that is

unlikely to ever be a valid schema name.

def hacked_get_colspec(element, schema='BOGUS_DEFAULT'): if not schema == 'BOGUS_DEFAULT': if schema is not None: return schema + "." + element.column.table.name + "." + element.column.key else: return element.column.table.name + "." + element.column.key

[Mike Bayer]

this patch should work. needs unit tests in test/engine/test_metadata.

Index: lib/sqlalchemy/schema.py
===================================================================
--- lib/sqlalchemy/schema.py    (revision 6730)
+++ lib/sqlalchemy/schema.py    (working copy)
@@ -43,6 +43,8 @@
            ]
 __all__.sort()

+RETAIN_SCHEMA = util.symbol('retain_schema')
+
 class SchemaItem(visitors.Visitable):
     """Base class for items that define a database schema."""

@@ -413,11 +415,11 @@
         """
         self.metadata.drop_all(bind=bind, checkfirst=checkfirst, tables=[self](self))

-    def tometadata(self, metadata, schema=None):
+    def tometadata(self, metadata, schema=RETAIN_SCHEMA):
         """Return a copy of this ``Table`` associated with a different ``MetaData``."""

         try:
-            if not schema:
+            if schema is RETAIN_SCHEMA:
                 schema = self.schema
             key = _get_table_key(self.name, schema)
             return metadata.tables[key](key)

[Mike Bayer]

test would be in test/engine/test_metadata.py

[Former user]

Original patch plus a test

[Michael Trier]

Fixed in e759031b16520a1389cd705c7a6c15cc894b226d. The attached patch is reversed.

[Mike Bayer]

Removing milestone: 0.6.0 (automated comment)