数据库不同表不同列的查询

第一个显示在listview中

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 WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection conn = new SqlConnection("server=.;database="+textBox1.Text+";uid=sa;pwd=123");
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = "select * from "+textBox2.Text;
            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            if (dr.HasRows)
            {
                listView1.Columns.Clear();//先清空一下列名
                for (int i = 0; i < dr.FieldCount; i++)
                {
                    listView1.Columns.Add(dr.GetName(i));//插入列名，dr.GetName(i)获取指定列的列名
                }
                listView1.Items.Clear();//清空一下行
                while (dr.Read())//读取到行
                {
                    ListViewItem lt = new ListViewItem();//新建一行的对象
                    for (int i = 0; i < dr.FieldCount; i++)
                    {

                        if (i == 0)
                        {
                            lt.Text = dr[i].ToString();//行第一列的数值
                        }
                        else
                        {
                            lt.SubItems.Add(dr[i].ToString());//行第一列之后的数值
                        }
                    }
                    listView1.Items.Add(lt);//把这一行加入Items集合
                }
            }
            conn.Close();
        }
    }
}

第二个显示在DataGridView中

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 WindowsFormsApplication3
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection conn = new SqlConnection("server=.;database=" + textBox1.Text + ";uid=sa;pwd=123");
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = "select * from " + textBox2.Text;
            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            DataTable dt = new DataTable();//创建DateTable新实例
            if (dr.HasRows)
            {
                dt.Columns.Clear();//清空一下dt中的列
                for (int i = 0; i < dr.FieldCount; i++)
                {
                    dt.Columns.Add(dr.GetName(i));//添加列名
                }
                
                while (dr.Read())
                {
                    DataRow dtr = dt.NewRow();//按dt的构架，新建行新实例
                    for (int i = 0; i < dr.FieldCount; i++)
                    {
                        dtr[i] = dr[i];//添加行中的数据，行的第一个数值对应dr.Read()读取到的第一个格数值，索引相对于
                    }
                    dt.Rows.Add(dtr);
                }
            }
            dataGridView1.DataSource = dt;//最后把dt赋给dataGridView1
            conn.Close();
        }
    }
}