Question

Using SQL Server 2005

Given a table:

| Role  | Low  | High |
| A     | AA00 | ZZ*  |
| B     | *    |      |
| C     | AA00 | AZ99 |

How would I go about performing a query that selects rows where a value falls within the LOW – HIGH range.

e.g. I would like to select Roles A and B if I am comparing Low and High to ‘BB’ and role B if I am comparing the range to ’22’

AB99 should return A, B, C

Answer 1

Try this:

DECLARE @CompVal VarChar(100) = '22';

WITH T AS (
  SELECT Role, Low, High
  FROM (
    SELECT 'A' Role, 'AA00' Low, 'ZZ*' High
    UNION
    SELECT 'B' Role, '*' Low, NULL High
    UNION
    SELECT 'C' Role, 'AA00' Low, 'AZ99' High
  ) U
)
SELECT *
FROM T
WHERE @CompVal BETWEEN Low AND High
  OR (@CompVal >= Low AND NULLIF(High, '*') IS NULL)
  OR (NULLIF(Low, '*') IS NULL AND @CompVal <= High)
;

I’m assuming that both your * and NULL values are used like wildcard values. This produces proper results for each of your example cases.

Note that this also depends on which collation you’re using. For most (including the default collation SQL_Latin1_General_CP1_CI_AS) it will be just fine.

EDIT: Looking more closely you may want to replace the WHERE clause with this:

WHERE @CompVal BETWEEN
      REPLACE(ISNULL(Low, '*'), '*', '0000')
  AND REPLACE(ISNULL(High, '*'), '*', 'ZZZZ')