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 第十五章_Command对象
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        SqlConnection A;

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                if (A.State == ConnectionState.Open || textBox1.Text != "")
                {
                    SqlCommand B = new SqlCommand();
                    B.Connection = A;
                    B.CommandText = "select count(*)from" + textBox1.Text.Trim();
                    B.CommandType = CommandType.Text;
                    int C = Convert.ToInt32(B.ExecuteScalar());
                    label1.Text = "数据表中共有:" + C.ToString() + "条数据";
                }
            }
            catch(Exception D)
            {
                label1.Text = D.Message;
            }
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            A = new SqlConnection("server=.;database=db_foavin;uid=sa;pwd=");
            A.Open();
        }
    }
}
为什么书上查有7条  我再怎么查也只有1条……
麻烦帮忙  谢谢！
我查询的是db_foavin下的tb_avin1表
里面建了5项
贴补了图  不好意思