- lazy loads for relationship attributes now use

the current state, not the "committed" state,
of foreign and primary key attributes
when issuing SQL, if a flush is not in process.
Previously, only the database-committed state would
be used.  In particular, this would cause a many-to-one
get()-on-lazyload operation to fail, as autoflush
is not triggered on these loads when the attributes are
determined and the "committed" state may not be
available.  [ticket:1910]

- A new flag on relationship(), load_on_pending, allows
the lazy loader to fire off on pending objects without a
flush taking place, as well as a transient object that's
been manually "attached" to the session. Note that this
flag blocks attribute events from taking place when an
object is loaded, so backrefs aren't available until
after a flush. The flag is only intended for very
specific use cases.

1 files changed, 25 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/util.py b/lib/sqlalchemy/sql/util.py
index c999ab786..bd4f70247 100644
--- a/lib/sqlalchemy/sql/util.py
+++ b/lib/sqlalchemy/sql/util.py
@@ -92,6 +92,31 @@ def find_columns(clause):
     visitors.traverse(clause, {}, {'column':cols.add})
     return cols
 
+def bind_values(clause):
+    """Return an ordered list of "bound" values in the given clause.
+
+    E.g.::
+    
+        >>> expr = and_(
+        ...    table.c.foo==5, table.c.foo==7
+        ... )
+        >>> bind_values(expr)
+        [5, 7]
+    """
+    
+    v = []
+    def visit_bindparam(bind):
+        value = bind.value
+        
+        # evaluate callables
+        if callable(value):
+            value = value()
+            
+        v.append(value)
+        
+    visitors.traverse(clause, {}, {'bindparam':visit_bindparam})
+    return v
+
 def _quote_ddl_expr(element):
     if isinstance(element, basestring):
         element = element.replace("'", "''")