Question

I’m working a DB design regarding how a user launched something.
My idea was to have timestamp (DateTime) column, and a method column (varchar).

This ‘method’ (varchar) could be anything:

• BUTTON_OK
• BUTTON_X
• APP_Y
• APP_Z
• etc

How can I COUNT the uses but group some values. In this case I want to have my result:

• BUTTONS: 20
• APP_X: 10
• APP_Z: 14

Answer 1

You need some way of defining which ‘methods’ fall into which ‘method group’.

One way would be to have a lookup table:

tbl_methodgroup

method_id    Method      Method_group
1            Button_OK   Buttons
2            Button_X    Buttons
3            App_Y       App_Y
4            App_Z       App_Z

then you could use:

select 
b.method_group, 
count(1) 
from
tbl_methodgroup a
  inner join tbl_method b on a.Method=b.Method
group by b.method_group

This method would have the advantage of being scalable as more methods get added. Rather than hand coding queries, which would need to be modified each time.