c# MySql连接池

c#端，MySQL连接池，废话不多说，直接上代码。一切都在代码里…

using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace MysqlHelper
{
    class SqlHelper
    {
        public static string ConnectionString = "database=smart_mine_phaseII;Password=123456;User ID=root;server=127.0.0.1;Charset=utf8";


        public static MySqlConnection getConnection()
        {
            return new MySqlConnection(ConnectionString);
        }

        public static int ExecuteNonQuery(String sqlText)
        {
            MySqlCommand cmd = new MySqlCommand();
            cmd.CommandTimeout = 5000;
            using (MySqlConnection conn = new MySqlConnection(ConnectionString))
            {
                conn.Open();
                cmd.Connection = conn;
                cmd.CommandText = sqlText;
                int value = cmd.ExecuteNonQuery();
                return value;
            }
        }
        public static MySqlDataReader ExecuteReader(String sqlText, MySqlConnection conn)
        {
            MySqlCommand cmd = new MySqlCommand();
            try
            {
                conn.Open();
                cmd.Connection = conn;
                cmd.CommandText = sqlText;
                MySqlDataReader reader = cmd.ExecuteReader();
                return reader;
            }
            catch (Exception e)
            {

                conn.Close();
                throw e;
                // return null;
            }
        }

        public static DataSet ExecuteDataSet(String sqlText)
        {
            MySqlCommand cmd = new MySqlCommand();
            DataSet ds = new DataSet();
            using (MySqlConnection conn = new MySqlConnection(ConnectionString))
            {
                conn.Open();
                cmd.Connection = conn;
                cmd.CommandText = sqlText;
                using (MySqlDataAdapter da = new MySqlDataAdapter())
                {
                    da.SelectCommand = cmd;
                    da.Fill(ds);
                    return ds;
                }
            }
        }

        public static DataTable ExecuteDataTable(String sqlText)
        {
            MySqlCommand cmd = new MySqlCommand();
            DataTable dt = new DataTable();
            using (MySqlConnection conn = new MySqlConnection(ConnectionString))
            {
                conn.Open();
                cmd.Connection = conn;
                cmd.CommandText = sqlText;
                using (MySqlDataAdapter da = new MySqlDataAdapter())
                {
                    da.SelectCommand = cmd;
                    da.Fill(dt);
                    return dt;
                }
            }
        }

        public static int getSingleInt(String sqlText)
        {
            MySqlCommand cmd = new MySqlCommand();
            MySqlConnection conn = new MySqlConnection(ConnectionString);
            try
            {
                conn.Open();
                cmd.Connection = conn;
                cmd.CommandText = sqlText;
                MySqlDataReader reader = cmd.ExecuteReader();
                reader.Read();
                if (reader.IsDBNull(0))
                    return 0;
                else
                    return reader.GetInt32(0);
            }
            catch (Exception e)
            {
                conn.Close();
                return -1;
            }
            finally { conn.Close(); }
        }
    }
}