- restored engine.echo flag

- changelog

3 files changed, 24 insertions, 0 deletions

diff --git a/CHANGES b/CHANGES
index 9974f08cf..732499d90 100644
--- a/CHANGES
+++ b/CHANGES
@@ -22,6 +22,10 @@ CHANGES
 - Fix to bind param processing such that "False" values (like blank strings)
   still get processed/encoded.
 
+- Fix to select() "generative" behavior, such that calling column(),
+  select_from(), correlate(), and with_prefix() does not modify the
+  original select object [ticket:752]
+  
 - Added a "legacy" adapter to types, such that user-defined TypeEngine
   and TypeDecorator classes which define convert_bind_param() and/or
   convert_result_value() will continue to function.  Also supports
diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py
index d3d96a711..c13c1d946 100644
--- a/lib/sqlalchemy/engine/base.py
+++ b/lib/sqlalchemy/engine/base.py
@@ -1010,6 +1010,7 @@ class Engine(Connectable):
         self.logger = logging.instance_logger(self, echoflag=echo)
 
     name = property(lambda s:sys.modules[s.dialect.__module__].descriptor()['name'], doc="String name of the [sqlalchemy.engine#Dialect] in use by this ``Engine``.")
+    echo = logging.echo_property()
     
     def __repr__(self):
         return 'Engine(%s)' % str(self.url)
diff --git a/lib/sqlalchemy/logging.py b/lib/sqlalchemy/logging.py
index 2dfd1e50a..2ced66109 100644
--- a/lib/sqlalchemy/logging.py
+++ b/lib/sqlalchemy/logging.py
@@ -75,4 +75,23 @@ def instance_logger(instance, echoflag=None):
     instance._should_log_debug = l.isEnabledFor(logging.DEBUG)
     instance._should_log_info = l.isEnabledFor(logging.INFO)
     return l
+
+class echo_property(object):
+    __doc__ = """when ``True``, enable log output for this element.
+
+    This has the effect of setting the Python logging level for the
+    namespace of this element's class and object reference.  A value
+    of boolean ``True`` indicates that the loglevel ``logging.INFO`` will be
+    set for the logger, whereas the string value ``debug`` will set the loglevel
+    to ``logging.DEBUG``.
+    """
+
+    def __get__(self, instance, owner):
+        if instance is None:
+            return self
+        else:
+            return instance._should_log_debug and 'debug' or (instance._should_log_info and True or False)
+
+    def __set__(self, instance, value):
+        instance_logger(instance, echoflag=value)
     
\ No newline at end of file