Question

I have a table

course     chapter          lessons

  2        Chapter1          3,4
  2        Chapter2          5,10,9,6,8
  2        Chapter3          11,15,16,18

I need the last value in lessons column like
In the 1st row of lessons i need the last digit 4
In the 2nd row of lessons i need the last digit 8
In the 3rd row of lessons i need the last digit 18

Answer 1

Is storing a comma separated list in a database column really that bad? Short answer: Yes, it is.

But until you normalize the table, you could use this:

SELECT course 
     , chapter
     , SUBSTRING_INDEX(lessons, ',', -1) AS last_lesson
FROM tableX