Question

I am trying to create a stored that will accept two values, a column name and a value. It will then check if there is a record that exists for the passed in column name with the passed in value. I’ve tried the following

CREATE PROCEDURE p_HasActiveReference
     @pi_colName varchar(100)
    ,@pi_colValue varchar(100)
AS
BEGIN
SET NOCOUNT ON      
    declare @sql varchar(1000)

    set @sql = 'IF EXISTS(SELECT TOP 1 p.PaymentId
                FROM Payments p
                WHERE ' + @pi_colName + ' = ' + @pi_colValue +     'AND Active = 1)

                    SELECT ''True'' AS RETVAL
                ELSE
                    SELECT ''False'' AS RETVAL'
    exec(@sql)  
 END

However, I always get this error

Conversion failed when converting the varchar value ‘InternalOr’ to data type int.

When I call the procedure with the following

p_HasActiveReference 'InternalOrgCode', '10110'

The internalOrgCode column is of value varchar(10)

I am not a SQL expert, so I am not even sure if what I need to achieve is even possible using that technique!

Thanks!

Answer 1

At least one issue: you should be surrounding your string value with single quotes, and to escape those inside a string you need to double them up:

WHERE ' + @pi_colName + ' = ''' + @pi_colValue + ''' AND ...

You also may want to declare your @sql variable as something bigger than 100 characters! Looks like your string is getting truncated.

If the possible values for @pi_colName are finite, the data type is always string, and the columns are collation compatible, you could do something like this and avoid dynamic SQL:

SELECT ...
WHERE CASE @pi_colName 
  WHEN 'col1' THEN col1
  WHEN 'col2' THEN col2
END = @pi_ColValue;