Queries
-------

.. _Filter.query_operator_to_q_operator:

How do I override what operator is used for a query?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The member `query_operator_to_q_operator` for `Filter` is used to convert from e.g. `:`
to `icontains`. You can specify another callable here:

.. code-block:: python

    Table(
        auto__model=Track,
        columns__album__filter__query_operator_to_q_operator=lambda op: 'exact',
    )

The above will force the album name to always be looked up with case
sensitive match even if the user types `album<Paranoid` in the
advanced query language. Use this feature with caution!

See also `How do I control what Q is produced?`_

.. _Filter.value_to_q:

How do I control what Q is produced?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

For more advanced customization you can use `value_to_q`. It is a
callable that takes `filter, op, value_string_or_f` and returns a
`Q` object. The default handles `__`, different operators, negation
and special handling of when the user searches for `null`.

.. code-block:: python

    class AlbumTable(Table):
        class Meta:
            auto__model = Album

            query__form__fields__eighties = Field.boolean(
                display_name="the '80s",
            )

            @staticmethod
            def query__filters__eighties__value_to_q(value_string_or_f, **_):
                if value_string_or_f == "1":
                    return Q(year__gte=1980) & Q(year__lte=1989)
                return Q()

.. raw:: html

    <div class="iframe_collapse" onclick="toggle('e7f4cebe-cdef-4b1e-87cd-67edf5e2a150', this)">▼ Hide result</div>
    <iframe id="e7f4cebe-cdef-4b1e-87cd-67edf5e2a150" src="doc_includes/cookbook_queries/test_how_do_i_control_what_q_is_produced.html" style="background: white; display: ; width: 100%; min-height: 100px; border: 1px solid gray;"></iframe>

.. raw:: html

    <div class="iframe_collapse" onclick="toggle('eef36f44-007b-4910-a899-b6ca2a56916f', this)">► Show result</div>
    <iframe id="eef36f44-007b-4910-a899-b6ca2a56916f" src="doc_includes/cookbook_queries/test_how_do_i_control_what_q_is_produced1.html" style="background: white; display: none; width: 100%; min-height: 100px; border: 1px solid gray;"></iframe>