new SqlParameter("@email",System.Data.SqlDbType.VarChar,100){Value=model.Email==null?DBNull.Value:(object)model.Email} model.Email = reader.IsDBNull(3) ? null : reader.GetString(3);
ado 数据库提交为Null
原文：http://www.cnblogs.com/xh0626/p/4812108.html
