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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.)
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We can also create a computed column using the Object explorer window. Go to your database, right click on tables, select “New Table” option. Create all columns that you require and to mark any column as computed, select that column and go to column Properties window and write your formula for computed column.
Some Limitations. You can not reference columns from other tables for a computed column expression directly. You can not apply insert or update statements on computed columns.
A computed column is a virtual column that is not physically stored in the table, unless the column is marked PERSISTED. A computed column expression can use data from other columns to calculate a value for the column to which it belongs.
To compute the mode, group by the browser column, get the COUNT(*) for each group, sort by that value, and take the record with the largest value. CL. Save this 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 If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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