EMS-员工信息管理系统
MySQL学习之基础操作总结
MySQL学习之基础命令实操总结
创建ems库
show databases;
create database ems;
use ems;创建user表
create table user(
id int primary key auto_increment,
name varchar(50),
salary double,
age int
);
插入表格数据
insert into user values(1,'zs',3000,20);
insert into user values(2,'ls',1000,30);
insert into user values(3,'ww',5000,25);
insert into user values(4,'xh',4000,23);
创建UserListServlets
使用JDBC连接数据库
将jar包复制的到lib文件夹下
//使用JDBC连接mysql数据库，将user表中的输出查询处理
ResultSet result=null;
Connection con=null;
try {
//(1)注册加载驱动
Class.forName("com.mysql.jdbc.Driver");
//(2)获得数据库的链接
//(1).连接mysql的url地址
String url="jdbc:mysql://localhost:3306/ems";
//(2).连接mysql的用户名
String username="root";
//(3).连接mysql的密码
String pwd="123456";
con=DriverManager.getConnection(url, username, pwd);
//(3)预编译sql语句
System.out.println("MySQL连接成功！"+con);
//3.预编译SQL语句
String sql="select * from user";
PreparedStatement prep=con.prepareStatement(sql);
//(4)执行sql语句
result=prep.executeQuery();
//(5)关闭
con.close();
} catch (Exception e) {
e.printStackTrace();
}package EMS;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
//员工信息查询的Servlet
public class UserListServlets extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//使用JDBC连接mysql数据库，将user表中的输出查询处理
ResultSet result=null;
Connection con=null;
try {
//(1)注册加载驱动
Class.forName("com.mysql.jdbc.Driver");
//(2)获得数据库的链接
//(1).连接mysql的url地址
String url="jdbc:mysql://localhost:3306/ems";
//(2).连接mysql的用户名
String username="root";
//(3).连接mysql的密码
String pwd="123456";
con=DriverManager.getConnection(url, username, pwd);
//(3)预编译sql语句
System.out.println("MySQL连接成功！"+con);
//3.预编译SQL语句
String sql="select * from user";
PreparedStatement prep=con.prepareStatement(sql);
//(4)执行sql语句
result=prep.executeQuery();
} catch (Exception e) {
e.printStackTrace();
}
//使用response,获得字符输出流PrintWriter,将查询出的结果输出到浏览器端
//设置格式编码
response.setContentType("text/html;charset=utf-8");
//向浏览器端输出一个表格
PrintWriter pw=response.getWriter();
pw.println("<table border='1' cellspacing='0' width='400' height='80' align='center'>");
pw.println("<caption>员工信息表</caption>");
pw.println("<tr align='center'>");
pw.println("<td>工号</td><td>姓名</td><td>工资</td><td>年龄</td>");
pw.println("</tr>");
try {
while(result.next())
{
pw.println("<tr align='center'><td>"+result.getInt("id")+"</td><td>"
+result.getString("name")+"</td><td>"+result.getDouble("salary")+"</td><td>"
+result.getInt("age")+"</td></tr>");
System.out.println(result.getInt("id")+"---"+result.getString("name")+"---&qu
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