Question

I have a SQL statement in C# (.NET Framework 4 running against SQL Server 2k8) that looks like this:

SELECT [Column1] FROM [Table1] WHERE [Column2] = @Column2

The above query works fine with the following ADO.NET code:

DbParameter parm = Factory.CreateDbParameter();
parm.Value = "SomeValue";
parm.ParameterName = "@Column2";
//etc...

This query returns zero rows, though, if I assign DBNull.Value to the DbParameter’s Value member even if there are null values in Column2. If I change the query to accommodate the null test specifically:

SELECT [Column1] FROM [Table1] WHERE [Column2] IS @Column2

I get an “Incorrect syntax near ‘@Column2′” exception at runtime. Is there no way that I can use null or DBNull as a parameter in the WHERE clause of a SELECT statement?

Answer 1

you may use

SELECT [Column1] FROM [Table1] WHERE [Column2] = ISNULL(@Column2 , 'value');

‘value’ can be any value that u want it to represent. If you want to match column2 that has null columns,

SELECT [Column1] FROM [Table1] WHERE ISNULL([Column2], 'value') = ISNULL(@Column2 , 'value');