Query
-----

Filter format
~~~~~~~~~~~~~

The filter format is partially inspired by https://www.parse.com/docs/rest#queries

operators
'''''''''

========    ========================
Key         Operation
========    ========================
``$lt``     Less Than
``$lte``    Less Than Or Equal To
``$gt``     Greater Than
``$gte``    Greater Than Or Equal To
``$ne``     Not Equal To
``$in``     Contained In
``$nin``    Not Contained in
``$or``     Or
``$and``    And
========    ========================
    

Filter attribute
''''''''''''''''

Exact match::

    {'attrname': value}


Other comparisons::

    {'attrname': {'$op': value, '$op2': othervalue}}

Use and/or::

    {'$or': {'attrname': value, 'attr2name': value}}
    {'$or': [
        {'attrname': value},
        {'attrname': {
            '$in': [1, 2, 3]}}]}

Filter relations
''''''''''''''''

If comparing by eid, same as attribute

Exact match::
    
    {'relname': eid}

Other::

    {"relname": {"$op": eid}}

Filter on relation target attributes/relations::

    {"relname": <entity filter>}

    {"relname": {"attrname": value}}

    {"relname": {"$or": {"attrname": value, "attr2name": ovalue}}}