using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;
using System.Text;

namespace Terra.YaoGan.Common
{
    public sealed class sqlserverHelper : IDatabaseInterface
    {
        private static readonly object lk = new object();
        private SqlConnection con = null;
        private static sqlserverHelper db = null;
        private string cstr = ConfigurationManager.ConnectionStrings["connString"].ConnectionString;

        #region  数据库连接
        public static sqlserverHelper  getInstance()
        {
            if (db == null)
            {
                lock (lk)
                {
                    if (db == null)
                    {
                        db = new sqlserverHelper();
                    }
                }
            }          
            return db;
        }
        
        public void connect()
        {
            try
            {
                con = new SqlConnection(cstr);
                if (con.State == ConnectionState.Closed)
                {
                    con.Open();
                }
            }
            catch (Exception e)
            {

            }
        }
        
        public void close()
        {
            try
            {
                if (con != null)
                {
                    con.Dispose();
                    con.Close();
                }
            } catch(Exception e)
            {

            }
        }

        public int getRow(string sql)
        {

            int result = -1;
            try
            {
                connect();
                result = new SqlCommand(sql, con).ExecuteNonQuery();
                close();
            }
            catch(Exception e)
            {
                close();
            }
            
            return result;
        }

        public DataTable QuerySql(string sql)
        {
            DataTable dt = new DataTable();
            try
            {
                connect();
                SqlCommand cmd = new SqlCommand(sql, con);
                SqlDataAdapter sda = new SqlDataAdapter(cmd);
                sda.Fill(dt);
                close();
            }
            catch(Exception e)
            {
                close();
            }
            
            return dt;
        }






        #endregion




    }
}