using System;
using System.Collections.Generic;
using System.Text;
using System.Data;
using MySql.Data.MySqlClient;

namespace i_salesDAL
{
    public class DBHelper
    {
        //引導資料庫連線資料庫呼叫Web.Config檔案   
        private static MySqlConnection connection;
        //建立連線
        public static MySqlConnection Connection
        {
            get
            {
                MySqlConnection myConn = new MySqlConnection("server=localhost;user id=root;password=root;database=google;CharSet=gb2312;");
                string connectionString = myConn.ConnectionString;
                if (connection == null)
                {
                    connection = new MySqlConnection(connectionString);
                    //開啟連線
                    connection.Open();
                }
                else if (connection.State == System.Data.ConnectionState.Closed)
                {
                    connection.Open();
                }
                else if (connection.State == System.Data.ConnectionState.Broken)
                {
                    connection.Close();
                    connection.Open();
                }
                return connection;
            }
        }
        //（無參）返回執行的行數(刪除修改更新)
        public static int ExecuteCommand(string safeSql)
        {
            MySqlCommand cmd = new MySqlCommand(safeSql, Connection);
            int result = cmd.ExecuteNonQuery();
            return result;
        }
        //（有參）
        public static int ExecuteCommand(string sql, params MySqlParameter[] values)
        {
            MySqlCommand cmd = new MySqlCommand(sql, Connection);
            cmd.Parameters.AddRange(values);
            return cmd.ExecuteNonQuery();
        }
        //（無參）返回第一行第一列(刪除修改更新)
        public static int GetScalar(string safeSql)
        {
            MySqlCommand cmd = new MySqlCommand(safeSql, Connection);
            int result = Convert.ToInt32(cmd.ExecuteScalar());
            return result;
        }
        //（有參）
        public static int GetScalar(string sql, params MySqlParameter[] values)
        {
            MySqlCommand cmd = new MySqlCommand(sql, Connection);
            cmd.Parameters.AddRange(values);
            int result = Convert.ToInt32(cmd.ExecuteScalar());
            return result;
        }
        //返回一個DataReader（查詢）
        public static MySqlDataReader GetReader(string safeSql)
        {
            MySqlCommand cmd = new MySqlCommand(safeSql, Connection);
            MySqlDataReader reader = cmd.ExecuteReader();
            return reader;
        }
        public static MySqlDataReader GetReader(string sql, params MySqlParameter[] values)
        {
            MySqlCommand cmd = new MySqlCommand(sql, Connection);
            cmd.Parameters.AddRange(values);
            MySqlDataReader reader = cmd.ExecuteReader();
            return reader;
        }

        //返回一個DataTable
        public static DataTable GetDataSet(string safeSql)
        {
            DataSet ds = new DataSet();
            MySqlCommand cmd = new MySqlCommand(safeSql, Connection);
            MySqlDataAdapter da = new MySqlDataAdapter(cmd);
            da.Fill(ds);
            return ds.Tables[0];
        }
        public static DataTable GetDataSet(string sql, params MySqlParameter[] values)
        {
            DataSet ds = new DataSet();
            MySqlCommand cmd = new MySqlCommand(sql, Connection);
            cmd.Parameters.AddRange(values);
            MySqlDataAdapter da = new MySqlDataAdapter(cmd);
            da.Fill(ds);
            return ds.Tables[0];
        }
    }
}