Create the alphabet recursively
The task of this exercise is to create the alphabet by using a recursive CTE.
To solve this task, you need to know that you can represent the letters from A
to Z
by a series of numbers from 65
to 90
. Accordingly, A
is represented by 65
and C
by 67
. The function char(number)
can be used to convert a number its corresponding letter.
This exercise is part of the course
Hierarchical and Recursive Queries in SQL Server
Exercise instructions
- Initialize
number_of_letter
to the number representing the letterA
. - Increase the value of
number_of_letter
by 1 in each step and set the limit to90
, the value ofZ
. - Select the recursive member from the defined CTE.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
WITH alphabet AS (
SELECT
-- Initialize letter to A
___ AS number_of_letter
-- Statement to combine the anchor and the recursive query
UNION ALL
SELECT
-- Add 1 each iteration
___ + ___
-- Select from the defined CTE alphabet
FROM ___
-- Limit the alphabet to A-Z
WHERE ___ < ___)
SELECT char(number_of_letter)
FROM alphabet;