呐，我问个问题，关于combobox和textbox还有datagridview。

下面是代码：
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.SqlClient;

namespace myobj
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private static SqlConnection conn;
        DataTable t1 = new DataTable();
        SqlDataAdapter da1 = new SqlDataAdapter();

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            //清空combobox2添加项
            this.comboBox2.Items.Clear();

            //清空combobox2中上次选择项
            this.comboBox2.Text = "";

            if (comboBox1.SelectedIndex == 0)
            {
                this.comboBox2.Items.Add("building");
                this.comboBox2.Items.Add("post");
                this.comboBox2.Items.Add("police");
                this.comboBox2.Items.Add("office");
                this.comboBox2.Items.Add("hospital");
            }
            else if (comboBox1.SelectedIndex == 1)
            {

                this.comboBox2.Items.Add("road");
                this.comboBox2.Items.Add("railway");
            }
            else
            {

                this.comboBox2.Items.Add("river");
                this.comboBox2.Items.Add("green");
            }
        }

        private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
           string i;
                string s1 = "";
                s1 = textBox1.Text;

                if (textBox1.Text.Length == 0)
                {
                    i = null;
                    //MessageBox.Show("请输入查询条件", "错误");
                }
                else
                {
                    i = Convert.ToString(textBox1.Text);
                    //连接数据库
                    conn = new SqlConnection("server = (local); Database = fzmap; Integrated Security= true;MultipleActiveResultSets=true");

                    //打开连接
                    conn.Open();

                    //创建命令

                    SqlCommand cmd = new SqlCommand();
                    cmd.Connection = conn;

                    cmd.CommandText = "select * from " + "'" + combobox2.Text + "' where name = " + "'" + textBox1.Text + "'";
                    //执行命令
                    DataSet dts = new DataSet();
                    SqlDataAdapter dat = new SqlDataAdapter(cmd);
                    dat.Fill(dts);
                    //将查询结果显示在DataGridView上
                    dataGridView1.DataSource = dts.Tables[0];

                    //关闭连接
                    conn.Close();
        }
    }
}

根据combobox2选择的内容选择sql里面的表，再在textbox1里输入名称，最后把有关内容显示在datagridview中。
代码有问题，但不知道错哪里
有没人帮忙看看代码，哪里有错？求指点啊 --------------------编程问答-------------------- 你的SQL语句有问题哦.因为"name"是关键字用于字段得加入"[]".
cmd.CommandText = "select * from " + "'" + combobox2.Text + "' where [name] = " + "'" + textBox1.Text + "'";
--------------------编程问答-------------------- 还有你的图片也挂了. --------------------编程问答-------------------- cmd.CommandText = "select * from " + "'" + combobox2.Text + "' where name = " + "'" + textBox1.Text + "'";

这语句这样写：“select * from "+combobox.text+" where name =‘“+textbox1.text+”’”
因为你拼的语句表加上单引号了 --------------------编程问答--------------------

cmd.CommandText = "select * from " + combobox2.Text + " where name ='" + textBox1.Text + "'";

--------------------编程问答-------------------- 表名不加单引号

补充：.NET技术 ,  C#