using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;



using System.Data;

using System.Data.SqlClient;



namespace Test

{

  public class DBHelper

  {

    public static string ConString = "Data Source=.;Initial Catalog=bankdb;User id=sa;Password=123;";



    //执行增删改的方法

    public static int RunNoQuery(string cmdText, CommandType cmdType, params SqlParameter[] pars)

    {

      SqlConnection con = new SqlConnection(ConString);

      con.Open();

      SqlCommand cmd = new SqlCommand(cmdText, con);

      cmd.CommandType = cmdType;

      if (pars != null  pars.Length > 0)

      {

        foreach (SqlParameter p in pars)

        {

          cmd.Parameters.Add(p);

        }

      }

      int rows = cmd.ExecuteNonQuery();

      con.Close();

      return rows;

    }



    //执行查询（DataSet）的方法

    public static DataSet RunSelect(string cmdText, CommandType cmdType, params SqlParameter[] pars)

    {

      SqlConnection con = new SqlConnection(ConString);

     

      SqlDataAdapter da = new SqlDataAdapter(cmdText, con);

      da.SelectCommand.CommandType = cmdType;

      if (pars != null  pars.Length > 0)

      {

        foreach (SqlParameter p in pars)

        {

          da.SelectCommand.Parameters.Add(p);

        }

      }

      DataSet ds = new DataSet();

      da.Fill(ds);



      return ds;

    }



    //执行查询得到一个值

    public static object RunOneValue(string cmdText, CommandType cmdType, params SqlParameter[] pars)

    {

      SqlConnection con = new SqlConnection(ConString);

      con.Open();

      SqlCommand cmd = new SqlCommand(cmdText, con);

      cmd.CommandType = cmdType;

      if (pars != null  pars.Length > 0)

      {

        foreach (SqlParameter p in pars)

        {

          cmd.Parameters.Add(p);

        }

      }

      object obj = cmd.ExecuteScalar();

      con.Close();

      return obj;

    }

  }

}