操作数类型冲突：nvarchar与Null Image的图像不兼容

Question

I have the following code: I am getting the following error message:

Operand type clash: nvarchar is incompatible with image 

when the code tries to do: cmd.ExecuteNonQuery(); Note that I get this error only when _ImageB is null . ImageB is stored as a Image Data type in the SQL Server table.

if (_ImageB == null)
{
    cmd.Parameters.AddWithValue("@ImageB", DBNull.Value);
}
else
{
    cmd.Parameters.AddWithValue("@ImageB", _ImageB);
}

Answer 1

尝试这个！

cmd.Parameters.Add("@ImageB", SqlDbType.Image).Value = _ImageB == null ? DBNull.Value : _ImageB;