Oracle SQL 插入语句中包含有时间问题

using System;
using System.Collections;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.Xml.Linq;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Data.OleDb;

namespace WebApplication1
{
    /// <summary>
    /// $codebehindclassname$ 的摘要说明
    /// </summary>
    [WebService(Namespace = "http://tempuri.org/")]
    [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
    public class updata : IHttpHandler
    {

        string StrConntion = "Provider=MSDAORA.1;Data Source=218;Persist Security Info=True;User ID=train;Password=jptrain";
        OleDbConnection con = null;
        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            context.Response.ContentType = "utf-8";
            string CarNo = context.Request["CarNo"];
            string Pic_Time = context.Request["Pic_Time"];
            string STATE = context.Request["STATE"];
            string OTHER = context.Request["OTHER"];
            string enterprisename = context.Request["enterprisename"];
            string time = DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss");
            string OID = "CK" + DateTime.Now.ToString("yyyyMMddhhmmss");
            using (con = new OleDbConnection(StrConntion))
            {
                string sql = "insert into camera_check (OID,CARTNO,ENTERPRISENAME,STATE,OTHER,TIME,TAKE_IMG_TIME) VALUES('"
                    + OID + "','" + CarNo + "','" + enterprisename + "','" + STATE + "','" + OTHER + "',to_date('" + time + "','yyyy-mm-dd hh24:mi:ss'),'" + Pic_Time + "')";
                OleDbCommand cmd = new OleDbCommand(sql, con);
                con.Open();
                cmd.ExecuteNonQuery();
                con.Close();
                cmd.Dispose();
            }
        }


        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}

时间一定要这样写：  to_date('2012-4-23 4:19:33','yyyy-mm-dd hh24:mi:ss')
如：Insert Into Good (time) Values(to_date('2012-4-23 4:19:33','yyyy-mm-dd hh24:mi:ss'));