Using vbNull to insert NULL into a sql server database table

Question

I need to insert text MALE or FEMALE into a table depending upon the user's input. I used to following code to insert but the code inserts value 1 if none (Male/Female) selected. ``` query = "INSERT INTO student_profile_table(gender) VALUES(@gender)" cmd = New SqlCommand(query, con) If rbtmale.Checked = True Then cmd.Parameters.AddWithValue("@gender", "Male") ElseIf rbtfemale.Checked = True Then cmd.Parameters.AddWithValue("@gender", "Female") Else cmd.Parameters.AddWithValue("@gender", vbNull) End If con.Open() cmd.ExecuteNonQuery() con.Close() ``` Need some suggestions/corrections

Accepted Answer

I believe you want `System.DbNull.Value` instead of `vbNull`.

`System.DbNull.Value` is the constant that SQL Server understands as null.

`vbNull` is intended to indicate if a Variant type is null.

Using vbNull to insert NULL into a sql server database table

Solution

Problem