From 0c560edee7d620bc2c4fcd820c1c04a3673d9b88 Mon Sep 17 00:00:00 2001
From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Wed, 20 Apr 2011 15:49:33 -0400
Subject: [PATCH] - Added explicit check for when Column .name is assigned as
 blank string [ticket:2140]

---
 CHANGES                          |  4 ++++
 lib/sqlalchemy/orm/strategies.py |  2 ++
 lib/sqlalchemy/schema.py         | 10 ++++++----
 test/sql/test_metadata.py        | 28 +++++++++++++++++++++++++---
 4 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/CHANGES b/CHANGES
index 72fc038c12..faa02e86ee 100644
--- a/CHANGES
+++ b/CHANGES
@@ -15,6 +15,10 @@ CHANGES
     fixed up some of the error messages tailored
     in [ticket:2069]
 
+- sql
+  - Added explicit check for when Column .name
+    is assigned as blank string [ticket:2140]
+
 - postgresql
   - Fixed the psycopg2_version parsing in the 
     psycopg2 dialect.
diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py
index acdac9984d..9c6d5bf1c4 100644
--- a/lib/sqlalchemy/orm/strategies.py
+++ b/lib/sqlalchemy/orm/strategies.py
@@ -118,6 +118,8 @@ class ColumnLoader(LoaderStrategy):
 
     def setup_query(self, context, entity, path, reduced_path, adapter, 
                             column_collection=None, **kwargs):
+#        import pdb
+#        pdb.set_trace()
         for c in self.columns:
             if adapter:
                 c = adapter.columns[c]
diff --git a/lib/sqlalchemy/schema.py b/lib/sqlalchemy/schema.py
index 45762490bc..bff3e8d635 100644
--- a/lib/sqlalchemy/schema.py
+++ b/lib/sqlalchemy/schema.py
@@ -901,15 +901,17 @@ class Column(SchemaItem, expression.ColumnClause):
             ["%s=%s" % (k, repr(getattr(self, k))) for k in kwarg])
 
     def _set_parent(self, table):
-        if self.name is None:
+        if not self.name:
             raise exc.ArgumentError(
-                "Column must be constructed with a name or assign .name "
-                "before adding to a Table.")
+                "Column must be constructed with a non-blank name or "
+                "assign a non-blank .name before adding to a Table.")
         if self.key is None:
             self.key = self.name
 
         if getattr(self, 'table', None) is not None:
-            raise exc.ArgumentError("this Column already has a table!")
+            raise exc.ArgumentError(
+                    "Column object already assigned to Table '%s'" % 
+                    self.table.description)
 
         if self.key in table._columns:
             col = table._columns.get(self.key)
diff --git a/test/sql/test_metadata.py b/test/sql/test_metadata.py
index 7ca31c8544..87d8ae5168 100644
--- a/test/sql/test_metadata.py
+++ b/test/sql/test_metadata.py
@@ -862,10 +862,32 @@ class ColumnDefinitionTest(AssertsCompiledSQL, fixtures.TestBase):
         for i, col in enumerate(tbl.c):
             assert col.name == c[i].name
 
-    def test_incomplete(self):
-        c = self.columns()
+    def test_name_none(self):
+
+        c = Column(Integer)
+        assert_raises_message(
+            exc.ArgumentError, 
+            "Column must be constructed with a non-blank name or assign a "
+            "non-blank .name ",
+            Table, 't', MetaData(), c)
+
+    def test_name_blank(self):
 
-        assert_raises(exc.ArgumentError, Table, 't', MetaData(), *c)
+        c = Column('', Integer)
+        assert_raises_message(
+            exc.ArgumentError, 
+            "Column must be constructed with a non-blank name or assign a "
+            "non-blank .name ",
+            Table, 't', MetaData(), c)
+
+    def test_dupe_column(self):
+        c = Column('x', Integer)
+        t = Table('t', MetaData(), c)
+
+        assert_raises_message(
+            exc.ArgumentError, 
+            "Column object already assigned to Table 't'",
+            Table, 'q', MetaData(), c)
 
     def test_incomplete_key(self):
         c = Column(Integer)
-- 
2.47.2