Question

I’m trying to write a query that will return the closest match from a table. The table represents a hierarchy, and looks like this:

Hier_Code Group1 Group2 Group3
_________ ______ ______ ______
A         1      1      5 
AA        1      2      5
AAA       1      2      5
AAB       1      3      5
AB        2      3      5
ABA       2      3      5
ABB       2      3      5

The values I’m searching for may not match perfectly, in which case I’d want them to ‘roll-up’ to the next level to find the match. For example:

Value     Returns:  
A         1      1      5 (Perfect match)
AAC       1      2      5 (AA is closest)
AABB      1      3      5 (AAB is closest)

The idea is that you would strip off one character at a time from the search term until you find a match. I’ve tried doing this with a recursive CTE, and also with a WHILE loop to no avail.

Any suggestions?

Thanks in advance

Answer 1

Try this:

SELECT top 1 Group1, Group2, Group3 
FROM temp 
WHERE 'AABB' like Hier_Code + '%'
GROUP BY Group1, Group2, Group3
ORDER BY MAX(len(Hier_Code)) desc