To get the nearest matching value in DB2 sql

Question

I have a table with the following values

   ACCNO                  TEXT
   -------------     ----------------
   8611004050001     internal payment
   861100405000X     external payment
   8611XXXXXXXXX     other payments

suppose if the accono is 8611004050002 then i have to pic external payment. if the accno is 8611211216223 then i have to get other payments.

I need to get the nearest matching value is single sql I have tried with case statement its not working. what is the efficient method to achieve this.

Pleas help me

Answer 1

Hmmm, one method uses a giant case statement. Something like this:

select t.*
from t
order by (case when accno = <accno> then 99
               when left(accno, 15) = left(<accno>, 15) then 15
               when left(accno, 14) = left(<accno>, 14) then 14
               when left(accno, 13) = left(<accno>, 13) then 13
               when left(accno, 12) = left(<accno>, 12) then 12
               when left(accno, 11) = left(<accno>, 11) then 11
               when left(accno, 10) = left(<accno>, 10) then 10
               when left(accno, 9) = left(<accno>, 9) then 9
               when left(accno, 8) = left(<accno>, 8) then 8
               when left(accno, 7) = left(<accno>, 7) then 7
               when left(accno, 6) = left(<accno>, 6) then 6
               when left(accno, 5) = left(<accno>, 5) then 5
               when left(accno, 4) = left(<accno>, 4) then 4
               when left(accno, 3) = left(<accno>, 3) then 3
               when left(accno, 2) = left(<accno>, 2) then 2
               when left(accno, 1) = left(<accno>, 1) then 1
               else 0
          end) desc
fetch first 1 row only;