How to concatenate strings with padding in sqlite

Question

I have three columns in an sqlite table:

    Column1    Column2    Column3
    A          1          1
    A          1          2
    A          12                  


        

Answer 1

Just one more line for @tofutim answer ... if you want custom field name for concatenated row ...

SELECT 
  (
    col1 || '-' || SUBSTR('00' || col2, -2, 2) | '-' || SUBSTR('0000' || col3, -4, 4)
  ) AS my_column 
FROM
  mytable;

Tested on SQLite 3.8.8.3, Thanks!