Question

I inherited a table with identifiers in a format [nonnumericprefix][number]. For example (ABC123; R2D2456778; etc). I was wondering if there was a good way to split this in SQL into two fields, the largest integer formed from the right side, and the prefix, for example (ABC, 123; R2D, 2456778; etc). I know I can do this with a cursor, C# code, etc – and I will if I have to – but I don’t run into things I cannot do fast and easily in SQL very often, so I thought I’d post it here.

Answer 1

1. Reverse the string
2. Use PATINDEX to find the first occurrence of a non numeric field
3. Use the LEFT function to return the numeric portion of the string

Code sample

DECLARE @myString varchar(100);
DECLARE @largestInt int;

SET @myString = 'R2D2456778'

SET @mystring = REVERSE(@myString);
SET @largestInt = LEFT(@myString, PATINDEX('%[a-z]%', @myString) - 1)

PRINT ( CONVERT(varchar(100), @largestInt) )