将值传递到SQL Server 2008中的表后如何获得行？

Question

I have a table named Test

Test
Name   Value1(varchar)   Value2(varchar)
A          1                  9
B          10                 19
C          20                 39
D          40                 45
...        ...                ...

Now how do I get Name from Test table when I send a value like '8' or '21'etc

Answer 1

Um, why are your columns VARCHAR ?

DECLARE @n INT = 8;

SELECT Name FROM dbo.Test
  WHERE @n BETWEEN CONVERT(INT, Value1) AND CONVERT(INT, Value2);

If you have other junk in these columns you may have to do something like this to prevent SQL Server from outsmarting you and trying to convert 'ascfdgt' to an integer:

DECLARE @n INT = 8;

SELECT Name FROM dbo.Test
  WHERE ISNUMERIC(Value1) = 1
    AND ISNUMERIC(Value2) = 1
    AND @n BETWEEN CASE WHEN ISNUMERIC(Value1) = 1 THEN CONVERT(INT, Value1) END
               AND CASE WHEN ISNUMERIC(Value2) = 1 THEN CONVERT(INT, Value2) END;

Now please, either fix the data type of this column, or store these numbers in a different column.

If you pass in A12 and need to find rows where Value1 is A010 and Value2 is A029 then it gets a little more complex:

DECLARE @n VARCHAR(12) = 'A12';

SELECT Name FROM dbo.Test
  WHERE ISNUMERIC(SUBSTRING(Value1, 2, 255)) = 1
    AND ISNUMERIC(SUBSTRING(Value2, 2, 255)) = 1
    AND CONVERT(INT, SUBSTRING(@n, 2, 255)) 
      BETWEEN CASE WHEN ISNUMERIC(SUBSTRING(Value1, 2, 255)) = 1
        THEN CONVERT(INT, SUBSTRING(Value1, 2, 255)) END
          AND CASE WHEN ISNUMERIC(SUBSTRING(Value2, 2, 255)) = 1
        THEN CONVERT(INT, SUBSTRING(Value2, 2, 255)) END;

See how ugly that is? Can you please, please, please consider fixing this terrible design so you don't have to litter your codebase with spaghetti queries like this?