错误是标准表达式中数据类型不匹配。

错误出现在最下面一行。其他的度可以执行！求高手指点，期末作业！原因也写出来了！
using System;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Data.SqlClient;

namespace _621007_赵武青
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
            OleDbConnection aConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Application.StartupPath + "/" + "DB.mdb");
            aConnection.Open();
            OleDbDataAdapter myadapter = new OleDbDataAdapter("select * from jidian", aConnection);
            DataSet ds = new DataSet();
            myadapter.Fill(ds);
            dataGridView1.DataSource = ds.Tables[0];//将dataGridView1与ds中的内容连接起来
        }

        private void button2_Click(object sender, EventArgs e)
        {
            OleDbConnection aConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Application.StartupPath + "/" + "DB.mdb");
            aConnection.Open();
            string strName;
            strName = "insert into jidian(dianhao,X,Y,Z) values(" + textBox1.Text + ",'" + textBox2.Text + "','" + textBox3.Text + "'," + textBox4.Text + ")";
            if (textBox1.Text == "" | textBox2.Text == "" | textBox3.Text == "" | textBox4.Text == "")
            {
                  MessageBox.Show("请填写要添加的数据");
                  return ;
            }
            OleDbDataAdapter myadapter = new OleDbDataAdapter(strName, aConnection); //执行查询
            DataSet ds = new DataSet(); //新建数据集
            myadapter.Fill(ds);//将SQL执行结果，填入数据集ds中可自加数据，进行验证
        }

        private void button3_Click(object sender, EventArgs e)
        {
            OleDbConnection aConnection = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Application.StartupPath + "/" + "DB.mdb");
            aConnection.Open();
            string strName;
            strName = "delete from jidian where dianhao=" + textBox1.Text;
            if (textBox1.Text == "")
            {
                MessageBox.Show("请输入点号");
                return;
            }
            OleDbDataAdapter myadapter = new OleDbDataAdapter(strName, aConnection);
            DataSet ds = new DataSet();
            myadapter.Fill(ds);           ///错误是标准表达式中数据类型不匹配。