Question

I have columns in my database called ModifyUser and ModifyDate that are supposed to show the username and date and time of the last person that has updated a specific product somehow.

I thought if I just added the second query then I would be fine, but for some reason the application wants to add ProductName into the Product table too. Why isn’t the application just inserting the 2 values I told it to insert in the Product table INSERT?

Error message: Cannot insert the value NULL into column 'ProductName', table
'Products.dbo.Product'; column does not allow nulls. INSERT fails.
The statement has been terminated.

'SQL INSERT: CompanyLink Table
        Dim strSQL As String = "INSERT INTO CompanyLink (ProductID, CompanyID) 
        VALUES (@ProductID, @CompanyID);INSERT INTO Product (ModifyDate, ModifyUser)
        VALUES (getdate(), @ModifyUser)"

    Using cn As New SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings("LocalSqlServer").ConnectionString)

    Using cmd As New SqlCommand(strSQL, cn)

    cmd.Parameters.Add(New SqlParameter("@ProductID", ProductID.Value))
    cmd.Parameters.Add(New SqlParameter("@CompanyID", company.Value))
    cmd.Parameters.Add(New SqlParameter("@ModifyUser",
    System.Web.HttpContext.Current.User.Identity.Name))

    cn.Open()
    cmd.ExecuteNonQuery()

Answer 1

The error message is pretty clear: your are not providing ProductName, which is a required (NOT NULL) field.

In order to fix it, you have to provide the ProductName, modifying this:

INSERT INTO Product (ModifyDate, ModifyUser, ProductName)
    VALUES (getdate(), @ModifyUser, @ProductName)

and add this:

cmd.Parameters.Add(New SqlParameter("@ProductName", SomeVariableContainingProductName))

Update

Since what you really need is an update, your statement will be:

Update product
set ModifyDate = getdate(),
    ModifyUser = @ModifyUser
where ProductID = @ProductID

Remember to provide all parameters values for the query.