如何在水晶报表的两个日期之间的数据

请帮我......我不知道有什么问题，我没有收到在报告中从两个的DateTimePicker选择两个日期之间的数据与代码.... plz帮助我

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Data.SqlClient;

 

namespace cargo

{

    public partial class Employee_Information : Form

    {

        SQLConnection db = new SQLConnection();

        public Employee_Information()

        {

            InitializeComponent();

        }

 

        private void button1_Click(object sender, EventArgs e)

        {

            try

            {

                string str1 = "select * from employeeinfo where Date between '" + dateTimePicker1.Text + "' and '"+dateTimePicker2.Text+"' ";

                db.cmd.Connection = db.conn;

                db.cmd.CommandText = str1;

                SqlDataAdapter da = new SqlDataAdapter(str1,db.conn);

                da.Fill(db.ds, "employeeinfo ");

                CrystalReport1 cr = new CrystalReport1();

                cr.SetDataSource(db.ds.Tables[0]);

                crystalReportViewer1.ReportSource = cr;

                crystalReportViewer1.RefreshReport();

            }

            catch (Exception ex)

            {

                MessageBox.Show("error in query" + ex.Message);

            }

        

 

        }

 

        private void Employee_Information_Load(object sender, EventArgs e)

        {

            db.DBConnect();

        }

 

        private void Employee_Information_FormClosed(object sender, FormClosedEventArgs e)

        {

            db.DBClose();

        }

 

       

    }

}