图书管理(c#数据库操作入门级示例代码)

【实例截图】

【核心代码】

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 BookManage
{
    public partial class add : Form
    {
        public add()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        
        private void add_Load(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=BookManage;Integrated Security=True");
            SqlDataAdapter adp = new SqlDataAdapter("select * from BookType", con);
            DataTable dt = new DataTable();
            adp.Fill(dt);
            comboBox1.DataSource = dt;
            comboBox1.DisplayMember = "typeName";
            comboBox1.ValueMember = "typeID";

        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                double d = Convert.ToDouble(textBox1.Text.Trim());
            }
            catch (Exception)
            {
                MessageBox.Show("图书编号只能是正整数！");
                textBox1.Text = "";
                textBox1.Focus();
                return;
            }
            try
            {
                double d = Convert.ToDouble(textBox4.Text.Trim());
            }
            catch (Exception)
            {
                MessageBox.Show("图书价格只能是正整数！");
                textBox4.Text = "";
                textBox4.Focus();
                return;
            }
            if (textBox1 .Text=="")
            {
                MessageBox.Show("图书编号不能为空！");
                textBox1.Focus();
                return;  
            }
            if (textBox2.Text == "")
            {
                MessageBox.Show("图书名称不能为空！");
                 textBox2.Focus();
                return;

            }
            if (textBox3.Text == "")
            {
                MessageBox.Show("图书作者不能为空！");
                 textBox3.Focus();
                return;

            }
            if (textBox4.Text == "")
            {
                MessageBox.Show("图书价格不能为空！");
                textBox4.Focus();
                return;

            }

            SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=BookManage;Integrated Security=True");
            SqlDataAdapter adp = new SqlDataAdapter("select * from BookInfo where bookCode='" textBox1 .Text  "'", con);
            DataTable dt = new DataTable();
            adp.Fill(dt);
            if (dt .Rows .Count >0)
            {
                MessageBox.Show("图书编号已存在！");
                return;
            }
            string Sql = "insert into BookInfo values('{0}','{1}','{2}','{3}','{4}',0)";
            Sql = string.Format(Sql,textBox1 .Text ,textBox2.Text ,comboBox1.SelectedValue .ToString (),textBox3 .Text ,textBox4 .Text );
            SqlCommand cmd = new SqlCommand(Sql,con);
            con.Open();
            int i = cmd.ExecuteNonQuery();
            con.Close();
            if (i > 0)
            {
                MessageBox.Show("图书添加成功！");
                textBox1.Text = "";
                textBox2.Text = "";
                textBox3.Text = "";
                textBox4.Text = "";
            }
            else
            {
                MessageBox.Show("添加失败！");
            }
        }

        
    }
}