using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Linq;
using System.Text;

namespace DirectService.Tools
{
    internal static class ListEx
    {
        /// <summary>
        /// 把列表转换为(*,*,*,*,...)字符串，空列表返回null
        /// </summary>
        public static string getString<T>(List<T> list)
        {
            string listString;
            
            if (list==null||list.Count<=0)
            {
                return null;
            }
            StringBuilder sb = new StringBuilder("(");
            switch (typeof(T).Name)
            {
                case "DateTime":
                case "String":
                    foreach (var item in list)
                    {
                        sb.Append("'" + item + "',");
                    }
                    break;
                default:
                    foreach (var item in list)
                    {
                        sb.Append(item + ",");
                    }
                    break;
            }
            listString = sb.ToString().TrimEnd(',')+')';
            return listString;
        }
    }
}