Q object encapsulates a SQL expression in a Python object that can be used in database-related operations. Using Q objects we can make complex queries with less and simple code.
For example, this Q object filters whether the question starts wiht 'what':
Q objects are helpfull for complex queries because they can be combined using logical operators and(&), or(|), negation(~)
For example, this statement returns if the question starts with 'who' or with 'what'.
The following code is source of Q class:
AND = 'AND'
OR = 'OR'
default = AND
def __init__(self, *args, **kwargs):
super(Q, self).__init__(children=list(args) + list(six.iteritems(kwargs)))
def _combine(self, other, conn):
if not isinstance(other, Q):
obj = type(self)()
obj.connector = conn
def __or__(self, other):
return self._combine(other, self.OR)
def __and__(self, other):
return self._combine(other, self.AND)
obj = type(self)()
As you can interpret from above code, we have three operators 'or', 'and' and invert(negation) and the default operator is AND.
This is an interesting feature as we can use the operator module to create dynamic queries.
We are performing the or operation using operator.or_
To use and operations simply execute:
Q objects not only simplify complex queries, they are very handy for dynamic filtering.
This is a simple way to integrate gitlab authentication in your django apps.
We can get user verified email id, general information, git lab URL ...
Coverage: It is a tool used for measuring the effectiveness of tests, showing the percentage of your codebase covered by tests.Test Coverage is an ...
Now we are going to index text content which is stored in structured files such as PDFs, Microsoft Office documents, images, etc using haystack and ...
MicroPyramid - India
HIG499, 6th phase KPHB, Hyderabad, India - 500072, +91 9959166266
Monday - Friday : 10:00 - 19:00
MicroPyramid - USA
280 Moon Clinton Rd,STE D Moon Twp, Pittsburgh, Pennsylvania 15108, +1 5102300949
MicroPyramid - UAE
Khalifa Building(Near Old Nesto Super Market),Opp Fire Station, Sharjah, UAE 341246, +971 566061239