一个简易的sqlhelper

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Configuration;

namespace DBUtility
{
    public class SQLHelper
    {
        public static readonly string ConnectionString = ConfigurationManager.ConnectionStrings["local"].ConnectionString;

        public static void PrepareCmd(SqlCommand cmd, SqlConnection conn, CommandType cmdType, string cmdTxt, System.Data.SqlClient.SqlParameter[] cmdParms)
        {
            if (conn.State != ConnectionState.Open)
                conn.Open();
            cmd.Connection = conn;
            cmd.CommandText = cmdTxt;
            cmd.CommandType = cmdType;
            if (cmdParms != null)
            {
                foreach (SqlParameter parm in cmdParms)
                    cmd.Parameters.Add(parm);
            }
        }

        public static SqlDataReader ExecuteReader(string constr, CommandType cmdType, string cmdTxt, SqlParameter[] commandParameters)