How can I query 'between' numeric data on a not numeric field?

Question

I\'ve got a query that I\'ve just found in the database that is failing causing a report to fall over. The basic gist of the query:

Select *
From table
Wher         


        

Answer 1

You'd have to force SQL to evaluate the expressions in a certain order. Here is one solution

Select *
From ( TOP 2000000000
   Select *
   From table
   Where IsNumeric(myField) = 1
   And IsNull(myField, '') <> ''
   ORDER BY Key
) t0
Where Convert(int, myField) Between @StartRange And @EndRange

and another

Select *
From table
Where

CASE
   WHEN IsNumeric(myField) = 1 And IsNull(myField, '') <> ''
   THEN Convert(int, myField) ELSE @StartRange-1
END Between @StartRange And @EndRange

• The first technique is "intermediate materialisation": it forces a sort on a working table.
• The 2nd relies on CASE ORDER evaluation is guaranteed
• Neither is pretty or whizzy

SQL is declarative: you tell the optimiser what you want, not how to do it. The tricks above force things to be done in a certain order.