Question

I have been working on a pretty large database this last week. Basically I am taking an Access database and converting it to a MySQL database. I have seccessfully converted all the tables and views to MySQL. However I have a view that requires input from the user, the date. The other view is the view that will be call.

view 1 – compiled_fourweeks – needs date
view 2 – metrics_fourweeks – uses `compiled_fourweeks in query.

I was thinking of a precedure but I won’t be able to reference the columns in the query.

I am kind of running out of ideas at this point.

Answer 1

If I understand correctly, you need to execute a view (metrics_fourweeks) that needs data from another view (compiled_fourweeks), and this last view requires input from the user.

I would go with the procedure approach:

create procedure fourWeeksData(d date)
    create or replace view compiled_fourweeks
        select ... 
        from ...   
        where recordDate = f  -- Just an example; use whichever where clause you need
        ...;

    select * from metrics_fourweeks;
end

If your database will be used just by a single user, your problem is solved. But if your database is meant to be used by more than one user… well, you can use temporary tables:

create procedure fourWeeksData2(d date)
    drop table if exists temp_compiled_fourweeks;
    create temporary table temp_compiled_fourweeks
        select ... 
        from ...   
        where recordDate = f  -- Just an example; use whichever where clause you need
        ...;
    -- You will need to create the required indexes for this new temp table

    -- Now replicate the SQL statement, using your new temp table
    select ... 
    from temp_compiled_fourweeks
    ...;
end

Hope this helps you.