- An informative error message is raised if a Column

which has not yet been assigned a name, i.e. as in
declarative, is used in a context where it is
exported to the columns collection of an enclosing
select() construct, or if any construct involving
that column is compiled before its name is
assigned.  [ticket:1862]

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/compiler.py b/lib/sqlalchemy/sql/compiler.py
index fcff5e355..e47db7e28 100644
--- a/lib/sqlalchemy/sql/compiler.py
+++ b/lib/sqlalchemy/sql/compiler.py
@@ -332,6 +332,10 @@ class SQLCompiler(engine.Compiled):
             
     def visit_column(self, column, result_map=None, **kwargs):
         name = column.name
+        if name is None:
+            raise exc.CompileError("Cannot compile Column object until "
+                                   "it's 'name' is assigned.")
+            
         if not column.is_literal and isinstance(name, sql._generated_label):
             name = self._truncated_identifier("colident", name)