Can I create computed columns in SQLite?
What would be the syntax (if it's possible), for example, to create a table called Car_Model that has a foreign key to a table Car_Make, and give Car_Make a column which is the number of Car_Models that exist of that Car_Make.
(If this seems trivial or homework-like it's because I am just playing with some python at home trying to recreate a problem I was having at work. We use MS-SQL at work.)
Answer
Update: As of version 3.31.0 (released on 2020-01-22), SQLite supports computed columns so the answer below applies to versions prior to 3.31.0
SQLite doesn't supported computed columns.
However your problem can be solved with a relatively simple SQL Query, you can then create a view to make it appear like a table with the extra computed columns.
SELECT Car_Make.Name, Count(*) AS Count
FROM Car_Make, Car_Model
WHERE Car_Make.Id = Car_Model.Make
GROUP BY Car_Make.Name
This should return a table similar to the following
Name Count
---- -----
Nissan 5
Toyota 20
Ford 10