Question

Currently I have a query which is partly based on a join on two tables according to two number columns within them.

Say one table has a number like 123456789999 (NUM1)

And the other table has a number ranging from 1 – 9999 (NUM2)

I want to pull out the records which have ‘NUM2’ within the 5th – 8th digits of ‘NUM1’

Currently I am doing something like this,

FROM Table1 AS T INNER JOIN Table2 AS S 
ON SUBSTRING(T.num1, 5, 4) = S.num2

I know it should be retrieving approx 100 records, but I only get 8. I believe it to be because of the small ranges within number two. Where have I gone wrong? OR how could my code be made more robust/effective?

Answer 1

You need to use CAST like this:

FROM Table1 AS T INNER JOIN Table2 AS S 
ON CAST(SUBSTRING(T.num1, 5, 4) AS INT) = S.num2

SEE THIS FIDDLE

For more info see SQL SERVER – Convert Text to Numbers (Integer) – CAST and CONVERT