DBhelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data;
using System.Data.SqlClient;
namespace WindowsFormsApplication1
{
    class DBhelper
    {

        public static SqlConnection conn;
        public static void connection() {
            conn = new SqlConnection();
            conn.Open();
        }
        //增加
        public static bool adm(string sqla) {
                        connection();
                        SqlCommand com = new SqlCommand(sqla, conn);
                        int pass = com.ExecuteNonQuery();
                        conn.Close();
                        return pass > 0;
        
        }
        //查询
        public static DataTable selectDB(string sqla) {

            DataTable dt = new DataTable();
            SqlDataAdapter dap = new SqlDataAdapter(sqla, conn);
            dap.Fill(dt);
            conn.Close();
            return dt;


        }


    }
}