Table Aliases?

[Gustavo Niemeyer]

Hello Akira,

> How does one declare and use table aliases?

Excellent question.. I've added another topic to the tutorial.

Copied below.  Please let me know if that answers the question
properly.


==== Aliases ====

So now let's say that we want to find every pair of people that work
for the same company.  I have no idea about why one would ''want'' to
do that, but that's a good case for us to exercise aliases.

First, we import `ClassAlias` into the local namespace (''mental note:
this should be in storm.locals as well''), and create a reference to it.

  >>> from storm.info import ClassAlias
  >>> AnotherEmployee = ClassAlias(Employee)

Nice, isn't it?

Now we can easily make the query we want, in a straightforward way:

  >>> result = store.find((Employee, AnotherEmployee),
  ...                     Employee.company_id == AnotherEmployee.company_id,
  ...                     Employee.id > AnotherEmployee.id)

  >>> for employee1, employee2 in result:
  ...     print (employee1.name, employee2.name)
  (u'Mike Mayer', u'Ben Bill')

Woah!  Mike and Ben work for the same company!

(Quiz for the attent reader: why is ''greater than'' being used in
the query above?)

-- 
Gustavo Niemeyer
http://niemeyer.net