//判断是否存在一条表项
        static public bool IsAnEntryExist(string merchant_id, string supplier_id, string batch_number, string id_in_batch)
        {
            //string db = " DATA SOURCE=localhost:1521/orcl2;USER ID=scott; password = 1234";
            //OracleConnection dbcon = new OracleConnection(db);
            Doselect  select  = Doselect.instance;
            Doexecute execute = Doexecute.instance;
            string    search  = "select merchant_id from merchandise where merchant_id = '" + merchant_id
                                + "' and supplier_id = '" + supplier_id
                                + "' and batch_number = '" + batch_number
                                + "' and id_in_batch = '" + id_in_batch
                                + "'";
            //OracleDataAdapter oda = new OracleDataAdapter(search, dbcon);
            //DataSet ds = new DataSet();
            //oda.Fill(ds, "merchandise");
            DataSet ds = select.Data(search, "merchandise");

            for (int i = 0; i < ds.Tables["merchandise"].Rows.Count; i++)
            {
                if (merchant_id == (string)ds.Tables["merchandise"].Rows[i]["merchant_id"])
                {
                    return(true);
                }
            }
            return(false);
        }
        public string find(string ID, string verification_code)
        {
            string   result = "";
            string   sql    = "select PASSWORD from STAFF_LOGIN where STAFF_ID = '" + ID + "' and verification_code = '" + verification_code + "'";
            Doselect a      = Doselect.instance;

            result = a.Do(sql).ToString();
            return(result);
        }
        public bool check(string ID, string password)
        {
            string   result = "";
            string   sql    = "select PASSWORD from STAFF_LOGIN where STAFF_ID = " + "'" + ID + "'";
            Doselect a      = Doselect.instance;

            result = a.Do(sql).ToString();
            if (result == password)
            {
                return(true);
            }
            return(false);
        }
        //通过货物名称查询
        static public DataSet SearchByName(string merchant_id, string name)
        {
            //string db = " DATA SOURCE=localhost:1521/orcl2;USER ID=scott; password = 1234";
            //OracleConnection dbcon = new OracleConnection(db);
            Doselect  select  = Doselect.instance;
            Doexecute execute = Doexecute.instance;
            string    search  = "select * from merchandise where merchant_id = '" + merchant_id + "' and name = '" + name + "'";
            //OracleDataAdapter oda = new OracleDataAdapter(search, dbcon);
            DataSet ds = new DataSet();

            //oda.Fill(ds, "merchandise");
            ds = select.Data(search, "merchandise");
            return(ds);
        }
        //查看商家所有货物数量信息
        static public DataSet ShowAllMerchandiseNumber(string merchant_id)
        {
            //string db = " DATA SOURCE=localhost:1521/orcl2;USER ID=scott; password = 1234";
            //OracleConnection dbcon = new OracleConnection(db);
            Doselect  select  = Doselect.instance;
            Doexecute execute = Doexecute.instance;
            string    search  = "select name, sum(amount) as sum_amount from merchandise where merchant_id = '" + merchant_id + "' group by name";
            //OracleDataAdapter oda = new OracleDataAdapter(search, dbcon);
            DataSet ds = new DataSet();

            //oda.Fill(ds, "merchandise");
            ds = select.Data(search, "merchandise");
            return(ds);
        }
        //判断某仓库是否有足够的空间
        static public double IsWarehouseCapacityEnough(string warehouse_id, double amount)
        {
            //string db = " DATA SOURCE=localhost:1521/orcl2;USER ID=scott; password = 1234";
            //OracleConnection dbcon = new OracleConnection(db);
            Doselect  select  = Doselect.instance;
            Doexecute execute = Doexecute.instance;
            string    search  = "select left_capacity from warehouse where warehouse_id = '" + warehouse_id + "'";
            //OracleDataAdapter oda = new OracleDataAdapter(search, dbcon);
            DataSet ds = new DataSet();

            //oda.Fill(ds, "warehouse");
            ds = select.Data(search, "warehouse");
            return(Convert.ToDouble(ds.Tables["warehouse"].Rows[0]["left_capacity"]) - amount);
        }
        public bool check(string ID, string password)
        {
            string   result = "";
            string   sql    = "select PASSWORD from MERCHANT_LOGIN where MERCHANT_ID = " + "'" + ID + "'";
            Doselect a      = Doselect.instance;

            //Doselect a1 = Doselect.instance;
            //if (a == a1) Console.WriteLine("the same!!!!");
            result = a.Do(sql).ToString();
            if (result == password)
            {
                return(true);
            }
            return(false);
        }
        public bool exist(string staff_id)//检查员工id是否存在
        {
            object   result = null;
            string   sql    = "select * from staff where staff_id='" + staff_id + "'";
            Doselect a      = Doselect.instance;

            result = a.Do(sql);
            if (result == null)
            {
                return(false);
            }
            else
            {
                return(true);
            }
        }
        static public DataSet selectReceipt(string supplier_id)
        {
            try
            {
                Doselect  select  = Doselect.instance;
                Doexecute execute = Doexecute.instance;

                string sql = "select * from receipt where supplier_id = '" + supplier_id + "' and merchant_id = '" + user_ifms.ID + "'";

                return(select.Data(sql, "receipt"));
            }
            catch
            {
                MessageBox.Show("查询失败。");
                return(null);
            }
        }
        public bool exist(string merchantID)
        {
            object result = null;

            string   sql = "select * from merchant where merchant_id='" + merchantID + "'";
            Doselect a   = Doselect.instance;

            result = a.Do(sql);
            if (result == null)
            {
                return(false);
            }
            else
            {
                return(true);
            }
        }
        //判断要取出的货物是否充足
        static public double IsMerchandiseEnough(string merchant_id, string supplier_id, string batch_number, string id_in_batch /*, string name*/, double amount_to_pick /*, string warehouse_id*/)
        {
            //string db = " DATA SOURCE=localhost:1521/orcl2;USER ID=scott; password = 1234";
            //OracleConnection dbcon = new OracleConnection(db);
            Doselect  select  = Doselect.instance;
            Doexecute execute = Doexecute.instance;
            string    search  = "select amount from merchandise where merchant_id = '" + merchant_id
                                + "' and supplier_id = '" + supplier_id
                                + "' and batch_number = '" + batch_number
                                + "' and id_in_batch = '" + id_in_batch
                                + "'";
            //OracleDataAdapter oda = new OracleDataAdapter(search, dbcon);
            DataSet ds = new DataSet();

            //oda.Fill(ds, "merchandise");
            ds = select.Data(search, "merchandise");
            return(Convert.ToDouble(ds.Tables["merchandise"].Rows[0]["amount"]) - amount_to_pick);
        }
        public bool update(string ID, string newpassword)
        {
            string result = "";

            string esql = "update STAFF_LOGIN set PASSWORD = '******' where STAFF_ID = '" + ID + "'";

            string ssql = "select PASSWORD from STAFF_LOGIN where STAFF_ID = '" + ID + "'";

            Doexecute b = Doexecute.instance;
            Doselect  a = Doselect.instance;

            b.Do(esql);
            result = a.Do(ssql).ToString();
            if (result == newpassword)
            {
                return(true);
            }
            return(false);
        }
        //判断某仓库是否属于某商家
        static public bool IsWarehouseBelongToMerchant(string warehouse_id, string merchant_id)
        {
            //string db = " DATA SOURCE=localhost:1521/orcl2;USER ID=scott; password = 1234";
            //OracleConnection dbcon = new OracleConnection(db);
            Doselect  select  = Doselect.instance;
            Doexecute execute = Doexecute.instance;
            string    search  = "select warehouse_id from warehouse where merchant_id = '" + merchant_id + "'";
            //OracleDataAdapter oda = new OracleDataAdapter(search, dbcon);
            DataSet ds = new DataSet();

            //oda.Fill(ds, "warehouse");
            ds = select.Data(search, "warehouse");
            for (int i = 0; i < ds.Tables["warehouse"].Rows.Count; i++)
            {
                if (warehouse_id == (string)ds.Tables["warehouse"].Rows[i]["warehouse_id"])
                {
                    return(true);
                }
            }
            return(false);
        }
        public bool update(string ID, string newpassword)
        {
            string result = "";

            string esql = "update MERCHANT_LOGIN set PASSWORD = '******' where MERCHANT_ID = '" + ID + "'";

            string    ssql = "select PASSWORD from MERCHANT_LOGIN where MERCHANT_ID = '" + ID + "'";
            Doexecute b    = Doexecute.instance;
            //Doexecute b1 = Doexecute.instance;
            //if (b == b1) Console.WriteLine("the same again!!");
            Doselect a = Doselect.instance;

            b.Do(esql);
            result = a.Do(ssql).ToString();


            if (result == newpassword)
            {
                return(true);
            }
            return(false);
        }