wince 连接本地数据库（C#)

 using System;        using System.Collections.Generic;        using System.ComponentModel;        using System.Data;        using System.Drawing;        using System.Text;        using System.Windows.Forms;        using System.Data.OleDb;        using System.Data.SqlServerCe;        using System.IO;        namespace ReadSDFFileOnDesktop        {        public partial class MainForm : Form          {            public static string strSQLPath = "DB.sdf";            public static string strConString = "Data Source = " + strSQLPath + "; Password = ";            public static string strAccessString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=Pub.mdb;";            public MainForm()            {                InitializeComponent();            }            private void buttonCreateDB_Click(object sender, EventArgs e)            {                // 创建数据库                if (File.Exists(strSQLPath))                {                    // 删除数据库                    File.Delete(strSQLPath);                    CreateDataBase();                }                else                {                    // 创建数据库                    CreateDataBase();                }            }            private void CreateDataBase()            {                // 创建数据库文件                SqlCeEngine engine = new SqlCeEngine(strConString);                engine.CreateDatabase();                engine.Dispose();                MessageBox.Show("数据库创建成功！");            }            private void buttonCreateTable_Click(object sender, EventArgs e)            {                if (File.Exists(strSQLPath))                {                    // 创建表                    SqlCeConnection cn = new SqlCeConnection(strConString);                    cn.Open();                    try                    {                        string strSQL = @"CREATE TABLE employee(emp_id nvarchar(9),                        fname nvarchar(20),minit nvarchar(1), lname nvarchar(30),                        job_id nvarchar(8),job_lvl nvarchar(8), pub_id nvarchar(4),                        hire_date datetime)";                        SqlCeCommand SqlCeCmd = new SqlCeCommand(strSQL, cn);                        SqlCeCmd.ExecuteNonQuery();                        MessageBox.Show("数据库中的表创建成功", "提示信息");                    }                    catch (SqlCeException ex)                    {                        MessageBox.Show(ex.Message);                    }                    finally                    {                        cn.Close();                    }                }                else                {                    MessageBox.Show("请先创建数据库！");                }            }            private void buttonImportData_Click(object sender, EventArgs e)            {                // 导入数据                OleDbConnection OleDbCn = new OleDbConnection(strAccessString);                try                {                    OleDbCn.Open();                    OleDbCommand OleDbCmd = new OleDbCommand("SELECT * FROM employee", OleDbCn);                    OleDbDataReader OleDbDr = OleDbCmd.ExecuteReader();                    SqlCeConnection SqlCeCn = new SqlCeConnection(strConString);                    try                    {                        SqlCeCn.Open();                        SqlCeCommand SqlCeCmd = new SqlCeCommand();                        SqlCeCmd.Connection = SqlCeCn;                        while (OleDbDr.Read())                        {                            string strSQL = "";                            strSQL = String.Format("INSERT INTO employee " +                            "(emp_id, fname, minit, lname, job_id, job_lvl, pub_id, hire_date)                            VALUES ('{0}', '{1}', '{2}', '{3}', '{4}', '{5}', '{6}', '{7}')",                            OleDbDr.GetValue(OleDbDr.GetOrdinal("emp_id")),                            OleDbDr.GetValue(OleDbDr.GetOrdinal("fname")),                            OleDbDr.GetValue(OleDbDr.GetOrdinal("minit")),                            OleDbDr.GetValue(OleDbDr.GetOrdinal("lname")),                            OleDbDr.GetValue(OleDbDr.GetOrdinal("job_id")),                            OleDbDr.GetValue(OleDbDr.GetOrdinal("job_lvl")),                            OleDbDr.GetValue(OleDbDr.GetOrdinal("pub_id")),                            OleDbDr.GetValue(OleDbDr.GetOrdinal("hire_date")));                            SqlCeCmd.CommandText = strSQL;                            SqlCeCmd.ExecuteNonQuery();                        }                        MessageBox.Show("数据导入成功！");                    }                    catch (SqlCeException ex)                    {                        MessageBox.Show(ex.Message);                    }                    finally                    {                        SqlCeCn.Close();                    }                }                catch (OleDbException ex)                {                    MessageBox.Show(ex.Message);                }                finally                {                    OleDbCn.Close();                }            }            private void buttonShowData_Click(object sender, EventArgs e)            {                // 显示数据                SqlCeConnection SqlCeCn = new SqlCeConnection(strConString);                try                {                    SqlCeCn.Open();                    string strSQL = "";                    strSQL = String.Format("SELECT * FROM employee ");                    SqlCeCommand SqlCeCmd = new SqlCeCommand(strSQL, SqlCeCn);                    SqlCeDataReader SqlCeDr = SqlCeCmd.ExecuteReader();                    listView1.Items.Clear();                    while (SqlCeDr.Read())                    {                        ListViewItem item;                        item = new ListViewItem(SqlCeDr.GetValue                        (SqlCeDr.GetOrdinal("emp_id")).ToString());                        item.SubItems.Add(SqlCeDr.GetValue(SqlCeDr.                        GetOrdinal("fname")).ToString());                        item.SubItems.Add(SqlCeDr.GetValue(SqlCeDr.                        GetOrdinal("minit")).ToString());                        item.SubItems.Add(SqlCeDr.GetValue(SqlCeDr.                        GetOrdinal("lname")).ToString());                        item.SubItems.Add(SqlCeDr.GetValue(SqlCeDr                        .GetOrdinal("job_id")).ToString());                        item.SubItems.Add(SqlCeDr.GetValue(SqlCeDr.                        GetOrdinal("job_lvl")).ToString());                        item.SubItems.Add(SqlCeDr.GetValue(SqlCeDr.                        GetOrdinal("pub_id")).ToString());                        item.SubItems.Add(SqlCeDr.GetValue(SqlCeDr.                        GetOrdinal("hire_date")).ToString());                        listView1.Items.Add(item);                    }                }                catch (SqlCeException ex)                {                    MessageBox.Show(ex.Message);                }                finally                {                    SqlCeCn.Close();                }            }          }        }