Question

I have a database with a table in it which has one field something like this.

Roll2011b45
Roll2011g40
Roll2010b03
Roll2010b90
Roll2009b16

I want to prepare a query such that I get output something like this

2009
2010
2011

The purpose is to find out all the tuples in a group manner with distinct set characters from 5th digit till 8th digit in that field. Can anyone help me with that please? Can someone help me with preparing such type of query?

Answer 1

This should do it:

SELECT SUBSTRING( column, 5, 4) FROM table GROUP BY 1 ORDER BY 1;