using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using System.Data;
namespace QuanLiBanHang
{
    class XulyDulieu
    {
        SqlConnection con;
        public XulyDulieu()
        {
            this.con = new SqlConnection();
            this.con.ConnectionString= @"Data Source=PHONGVU\SQLEXPRESS;Initial Catalog=QLBH_CS414;Integrated Security=True";
        }
        public void Moketnoi()
        {
            if (con.State == System.Data.ConnectionState.Closed)
                con.Open();
        }
        public void Dongketnoi()
        {
            if (con.State == System.Data.ConnectionState.Open)
                con.Close();
        }
        /// <summary>
        /// Thực thi sql(select*from)
        /// Trả về kiểu dl bảng DataTable
        /// </summary>
        /// <param name="sql">sql=select*from...</param>
        /// <returns></returns>
        public DataTable table(string sql)
        {
            this.Moketnoi();
            DataTable tb = new DataTable();
            SqlDataAdapter adp = new SqlDataAdapter(sql, con);
            adp.Fill(tb);
            this.Dongketnoi();
            return tb;
        }
        /// <summary>
        /// Thực thi sql(insert into,delete,update)
        /// Trả về hai giá trị (0 và <>0)
        /// nếu=0 thành công
        /// nếu <> không thành công
        /// </summary>
        /// <param name="sql"></param>
        /// <returns></returns>
        public int ThucthiSql(string sql)
        {
            int result = 0;
            this.Moketnoi();
            SqlCommand cmd = new SqlCommand(sql,con);
            result = (int)cmd.ExecuteNonQuery();
            this.Dongketnoi();
            return result;
        }
    }
}