JDBC&javaweb連接sqlServer數據庫&增刪改查

實踐出真知看實例：

步驟

1.首先建庫建表爲連接做準備

2.建web項目導入sqlServer jar包

3.創建Util工具類根據表新建javabean

4.編寫查詢方法

5.整合代碼

詳解 ⬇⬇⬇⬇⬇⬇

1.建庫建表爲連接做準備

	--建庫
	create database Demo
		on(
		name='StuMessage',
		filename ='D:\Demo.mdf',
		size=10mb,
		filegrowth=10%
	)
	--建表
	use Demo
	create table users(
	id int,
	name varchar(36),
	sex varchar(8)
	)

2.jar包

jar包地址

3.創建Util工具類根據表新建javabean

1.創建Util工具類

	import java.sql.Connection;
	import java.sql.DriverManager;
	import java.sql.PreparedStatement;
	import java.sql.ResultSet;
	import java.sql.SQLException;
	import java.sql.Statement;
	
	public class Util {
	
	/**
	 * 獲取Connection
	 * @return
	 */
public  Connection getConn(){
	Connection conn = null;
	try {
									//驅動包位置
		Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
	} catch (ClassNotFoundException e) {
		// TODO Auto-generated catch block
		System.out.println("驅動加載失敗");
		e.printStackTrace();
	}		
	try {
						//sqlServer連接和數據庫名
		String url ="jdbc:sqlserver://localhost:1433;databaseName=Demo";
		String user ="sa";//數據庫賬號
		String pwd = "1";//數據庫密碼
		conn=DriverManager.getConnection(url,user,pwd);
	} catch (SQLException e) {
		System.out.println("數據庫連接失敗");
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
	System.out.println("連接成功");
	return conn;
}
/**
 * 關閉資源
 * @param conn
 * @param st
 * @param rs
 */
public  void close(Connection conn , PreparedStatement st ,ResultSet rs){
	try {
		if(conn!=null){conn.close();}
		if(st!=null){st.close();}
		if(rs!=null){rs.close();}
	} catch (SQLException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}		
}

2.根據表創建javaBean

	public class Users {

private int id ;
private String name ;
private String sex ;
public Users() {
	super();
	// TODO Auto-generated constructor stub
}
public int getId() {
	return id;
}
public void setId(int id) {
	this.id = id;
}

public String getName() {
	return name;
}
public void setName(String name) {
	this.name = name;
}
public String getSex() {
	return sex;
}
public void setSex(String sex) {
	this.sex = sex;
}
}

4.編寫增刪改查類

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import cn.msg.bean.Users;
import cn.msg.util.Util;

public class UserServers {
	private  PreparedStatement ps = null;
	private  Connection conn = null;
	private  ResultSet rs = null;
	private  Util util = new Util();
	/**
	 * 獲取一條信息
	 * @param id
	 * @return Users
	 */
	public  Users getUser(int id){	
		String sql = "select * from Users Where id = ? ";
		conn = util.getConn();
		try {
			ps = conn.prepareStatement(sql);
			ps.setInt(1, id);
			rs=ps.executeQuery();
			if(rs.next()){
				Users user = new Users();
				user.setId(rs.getInt(1));
				user.setName(rs.getString(2));
				user.setSex(rs.getString(3));
				return user;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			util.close(conn, ps, rs);
		}
		Users user = new Users();
		user.setId(0);
		user.setName("無此條信息");
		user.setSex("無此條信息");
		return user;
	}
	/**
	 * 獲取Users表
	 * @param table
	 * @return ArrayList<Users>
	 */
	public  ArrayList<Users> getUsers(){
		ArrayList<Users> list = new ArrayList<Users>();
		String sql = "select * from users";
		conn=util.getConn();
		try {
			ps=conn.prepareStatement(sql);
			//ps.setString(1, table);
			rs=ps.executeQuery();
			while(rs.next()){
				Users user = new Users();
				user.setId(rs.getInt(1));
				user.setName(rs.getString(2));
				user.setSex(rs.getString(3));
				list.add(user);
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			util.close(conn, ps, rs);
		}
		//若表中沒有信息
		if(list.size()==0){
		Users user = new Users();
		user.setId(-1);
		user.setName("表中無信息");
		user.setSex("表中無信息");
		list.add(user);
		}
		return list;
	}
	/**
		 *添加一條信息
		 * @param id
		 * @param name
		 * @param sex
		 * @return返回true添加成功false添加失敗
		 */
	public Boolean insert(int id , String name , String sex){
		String sql = "insert into users values(?,?,?)";
		conn = util.getConn();
		try {
			ps=conn.prepareStatement(sql);
			ps.setInt(1, id);
			ps.setString(2, name);
			ps.setString(3, sex);
			if(ps.executeUpdate()>0){
				return true;
			}else{
				return false;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			util.close(conn, ps, rs);
		}
		return null;		
	}
	/**
	 * 根據id刪除一條信息
	 * @param id
	 * @return
	 */
	public Boolean delete(int id){
		String sql = "delete from users where id=?";
		conn = util.getConn();
		
		try {
			ps = conn.prepareStatement(sql);
			ps.setInt(1, id);
			if(ps.executeUpdate()>0){
				return true;
			}else{
				return false;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			util.close(conn, ps, rs);
		}
		
		return null;
	}
	/**
	 * 根據id更新數據
	 * @param id
	 * @param name
	 * @param sex
	 * @return
	 */
	public Boolean update(int id , String name , String sex){
		String sql = "update users set name = ?,sex = ? where id = ?";
		conn = util.getConn();
		try {
			ps=conn.prepareStatement(sql);
			ps.setString(1, name);
			ps.setString(2, sex);
			ps.setInt(3, id);
			if(ps.executeUpdate()>0){
				return true;
			}else{
				return false;
			}
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			util.close(conn, ps, rs);
		}
		return null;		
	}		
}

5.整合代碼

1.jsp頁面代碼

	<body>
   <%
   	UserServers stu = new UserServers();
      ArrayList<Users> list = new ArrayList<Users>();
     list = stu.getUsers();
   %>
   <h1>數據庫增刪改查</h1>
   <br>
   添加信息:
 <form action="servlet/insert">
  id:<input type="number" name="id">
  name:<input type="text" name = "name">
  sex:<input type = "text" name = "sex">
  <button>確認</button><br>
 </form>
 更新信息（根據id更新）:
 <form action="servlet/update">
  id:<input type="number" name="id">
  name:<input type="text" name = "name">
  sex:<input type = "text" name = "sex">
  <button>確認</button><br>
 </form>
   根據ID刪除信息：
   <form action="servlet/delete">
   <input type="number" name="delete"><button onclick="">確認</button><br>
   </form>
   <h1>信息顯示</h1>
   <table>
   <tr><th>ID</th><th>Name</th><th>Sex</th></tr>
   <%for(Users user : list){
   		%>
   		<tr>
   			<td><%=user.getId() %></td>
   			<td><%=user.getName() %></td>
   			<td><%=user.getSex() %></td>
   		<%
   } %>
   </table>
  </body>

由jsp代碼可以看出做不同的操作需要用不同的servlet做後臺處理輸入的信息

2.對添加信息做支持的Servlet

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import cn.msg.servers.UserServers;

public class insert extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		request.setCharacterEncoding("utf-8");//防止亂碼
	response.setContentType("text/html");
	PrintWriter out = response.getWriter();
	UserServers stu = new UserServers();//實例化剛剛編寫的查詢方法
	//獲取傳值
     int id = Integer.parseInt(request.getParameter("id"));
     String name = new String(request.getParameter("name").getBytes("ISO-8859-1"),"utf-8");
     String sex = new String(request.getParameter("sex").getBytes("ISO-8859-1"),"utf-8");
     //調用插入信息的方法
     stu.insert(id, name, sex);
     //重定向到主頁面
    response.sendRedirect("http://127.0.0.1:8080/Demo10.15/");
	out.flush();
	out.close();
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
			doGet(request, response);
	}

}

3.對更新信息做支持的Servlet

	import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import cn.msg.servers.UserServers;

public class update extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException {

	request.setCharacterEncoding("utf-8");
	response.setContentType("text/html");
	PrintWriter out = response.getWriter();
	UserServers stu = new UserServers();//實例化剛剛編寫的查詢方法類
	//接收傳值
     int id = Integer.parseInt(request.getParameter("id"));
     String name = new String(request.getParameter("name").getBytes("ISO-8859-1"),"utf-8");
     String sex = new String(request.getParameter("sex").getBytes("ISO-8859-1"),"utf-8");
     //調用更新方法
     stu.update(id, name, sex);
     //重定向到主頁面
    response.sendRedirect("http://127.0.0.1:8080/Demo10.15/");
	out.flush();
	out.close();
}
public void doPost(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException {

	doGet(request, response);
}

}

4.對刪除信息做支持的Servlet

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import cn.msg.servers.UserServers;

public class delete extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		response.setContentType("text/html");
		PrintWriter out = response.getWriter();
		UserServers stu = new UserServers();
	    int id = Integer.parseInt(request.getParameter("delete"));
	    System.out.println(id);
	    stu.delete(id);
	    response.sendRedirect("http://127.0.0.1:8080/Demo10.15/");
		out.flush();
		out.close();
	}

	
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}