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。

我看了你的代码，你出错的这行代码，其实上面2个函数都调用了同样的代码。
那么为什么上面的函数没有问题，而这里就出错了呢？ 有可能是参数问题，你自己调试调试。。。

我只写段代码给你看看，什么是执行删除或修改方法，什么是查询的方法.我这里是独立成连接类的，你可以无视

程序代码：

[color=#0000FF]public int RunExec(string sql)
        {
            try
            {
                DBHelp db = new DBHelp();
                SqlConnection conn = db.Getconn();
[/color]                SqlCommand cmd = new SqlCommand(sql, conn);
                int i = cmd.ExecuteNonQuery();
                db.CloseConn();
                return i;
            }
            catch (SqlException ex)
            {
                return 0;
            }
        }

        public DataSet GetDataSet(string sql)
        {
                DBHelp db = new DBHelp();
                SqlConnection conn = db.Getconn();
                DataSet ds = new DataSet();
                SqlDataAdapter sda = new SqlDataAdapter(sql,conn);         
                sda.Fill(ds, "clin");
                db.CloseConn();
                return ds;         
        }     

才看到你最后一句话。当我啥也没说，我没本事，你们老师有本事。以后有事去求你老师吧，执行删除和修改都能用SqlDataAdapter

[ 本帖最后由 mpi 于 2012-12-19 11:34 编辑 ]

没学SQl语言！没学C#

以上代码为老师平时实习用的！我只是略该，但是整体结构没错！你要又能耐给我把问题改出来！