doc/book/annexes/rql/debugging.rst
author Sylvain Thénault <sylvain.thenault@logilab.fr>
Fri, 08 Jul 2016 10:17:14 +0200
changeset 11415 f87da59faea1
parent 10491 c67bcee93248
child 12716 f5300acd8f4f
permissions -rw-r--r--
[migration] Test and fix case of addition of an attribute with some serialized constraint It was crashing on attempt to remove an unexisting constraint. This code may be removed safely as it's expected to be handled by the constraint removal hook. Notice that adding a vocabulary on shortpara makes yams change the varchar max size. This is arguable but not the point of this test, so simply adapt the max size defined in the schema coherently so we don't have to bother with that at this point.

.. -*- coding: utf-8 -*-

.. _DEBUGGING:

Debugging RQL
-------------

Available levels
~~~~~~~~~~~~~~~~

Server debugging flags. They may be combined using binary operators.

.. autodata:: cubicweb.server.DBG_NONE
.. autodata:: cubicweb.server.DBG_RQL
.. autodata:: cubicweb.server.DBG_SQL
.. autodata:: cubicweb.server.DBG_REPO
.. autodata:: cubicweb.server.DBG_MS
.. autodata:: cubicweb.server.DBG_HOOKS
.. autodata:: cubicweb.server.DBG_OPS
.. autodata:: cubicweb.server.DBG_MORE
.. autodata:: cubicweb.server.DBG_ALL


Enable verbose output
~~~~~~~~~~~~~~~~~~~~~

To debug your RQL statements, it can be useful to enable a verbose output:

.. sourcecode:: python

    from cubicweb import server
    server.set_debug(server.DBG_RQL|server.DBG_SQL|server.DBG_ALL)

.. autofunction:: cubicweb.server.set_debug

Another example showing how to debug hooks at a specific code site:

.. sourcecode:: python

    from cubicweb.server import debugged, DBG_HOOKS
    with debugged(DBG_HOOKS):
        person.cw_set(works_for=company)


Detect largest RQL queries
~~~~~~~~~~~~~~~~~~~~~~~~~~~

See `Profiling and performance` chapter (see :ref:`PROFILING`).


API
~~~

.. autoclass:: cubicweb.server.debugged