SQL 挑错解决方案

//以下的 SQL语句 用得正确吗? 可以用"@dataTable" 这样的参数吗?
 public bool delEmailAccount(int nodeId, string dataTable, string userName)
        {
             OleDbParameter[] parameters = { 
                                                new OleDbParameter("@dataTable",dataTable),
                                                 new OleDbParameter("@nodeId", nodeId),
                                                 // new OleDbParameter("@userName", userName),
            };

             return DBhelper.ExecuteNonqueryBool("delete from @dataTable where id=@nodeId", parameters);
        }

     //为什么以下的语句操作不了数据库的数据?
        public bool delEmailAccount(int nodeId, string dataTable, string userName)
        {
             OleDbParameter[] parameters = { 
                                               //这里为什么就不能用下面的参数方式来执行操作呢?
                                                //new OleDbParameter("@dataTable",dataTable),
                                                 new OleDbParameter("@nodeId", nodeId),
                                                 // new OleDbParameter("@userName", userName),
            };

             return DBhelper.ExecuteNonqueryBool("delete from " + dataTable + " where id=@nodeId", parameters);
        }


     //而以下的语句却可以呢?
        public bool delEmailAccount(int nodeId, string dataTable, string userName)
        {
             OleDbParameter[] parameters = { 
                                                //new OleDbParameter("@dataTable",dataTable),
                                                // new OleDbParameter("@nodeId", nodeId),
                                                 // new OleDbParameter("@userName", userName),
            };

             return DBhelper.ExecuteNonqueryBool("delete from " + dataTable + " where id=" + nodeId, parameters);
        }

    //添加搜索结果到数据库
        public bool addToDataBase(emailSearchSys_model model)
        {
            OleDbParameter[] parameters = { 
            new OleDbParameter("@CustomerEmail", model.CustomerEmail),
            new OleDbParameter("@CustomerPhone", model.CustomerPhone),
            new OleDbParameter("@CustomerNote", model.CustomerNote),
            new OleDbParameter("@categoryId", model.CategoryId),
            new OleDbParameter("@categoryName", model.CategoryName),
            new OleDbParameter("@userName", model.UserName),
        };

            return DBhelper.ExecuteNonqueryBool("insert into CustomerData (email,phone,cmsNote,categoryId,categoryName,userName)"
+"values (@CustomerEmail,@CustomerPhone,@CustomerNote,@categoryId,@categoryName,@userName)", parameters);
        }