大数据之路week05--day01（JDBC 初识之实现一个系统 实现用户选择增删改查 未优化版本）

要求，实现用户选择增删改查。

给出mysql文件，朋友们可以自己运行导入到自己的数据库中：

/*
Navicat MySQL Data Transfer

Source Server         : mysql
Source Server Version : 50557
Source Host           : 127.0.0.1:3306
Source Database       : school

Target Server Type    : MYSQL
Target Server Version : 50557
File Encoding         : 65001

Date: 2019-12-02 21:20:56
*/

SET FOREIGN_KEY_CHECKS=0;

-- ----------------------------
-- Table structure for t_student
-- ----------------------------
DROP TABLE IF EXISTS `t_student`;
CREATE TABLE `t_student` (
  `sid` int(11) NOT NULL,
  `sname` varchar(10) NOT NULL,
  `gender` varchar(2) NOT NULL,
  `Classid` int(11) NOT NULL,
  PRIMARY KEY (`sid`),
  UNIQUE KEY `UK_SNAME` (`sname`),
  KEY `UF_SCLASS` (`Classid`),
  CONSTRAINT `UF_SCLASS` FOREIGN KEY (`Classid`) REFERENCES `t_class` (`cid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

-- ----------------------------
-- Records of t_student
-- ----------------------------
INSERT INTO `t_student` VALUES ('1604093001', '埼玉', '男', '6');
INSERT INTO `t_student` VALUES ('1604093002', '李宏灿', '男', '5');
INSERT INTO `t_student` VALUES ('1604093005', '娘口三三', '男', '6');
INSERT INTO `t_student` VALUES ('1604093024', '路飞', '男', '5');
INSERT INTO `t_student` VALUES ('1604093025', '齐博源', '男', '6');
INSERT INTO `t_student` VALUES ('1604093026', '比较好', '男', '6');
INSERT INTO `t_student` VALUES ('1604093029', '赵以浩', '男', '6');
INSERT INTO `t_student` VALUES ('1604093030', '大雄', '男', '6');

系统实现代码：

package MySQL测试连接;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Scanner;

/**
 * 
 * 创建时间：2019年12月2日 上午10:11:28
 * 
 * 项目名称：MySQL_Test
 * 
 * @author WYH
 * 
 * @version 1.0
 * 
 * @since JDK 1.8.0
 * 
 *        文件名称：Test5.java
 * 
 *        类说明：
 *            对数据库操作的增删改查系统1.0版本
 */

public class Test5 {
    private static Connection conn = null;
    private static PreparedStatement ps = null;
    private static ResultSet rs = null;

    // 添加
    public static void insertSql(String sql, Connection conn, int sid,
            String sname, String gender, int Classid) {
        try {
            ps = conn.prepareStatement(sql);
            ps.setInt(1, sid);
            ps.setString(2, sname);
            ps.setString(3, gender);
            ps.setInt(4, Classid);
            int i = ps.executeUpdate();
            System.out.println("有" + i + "记录被影响,成功添加一条数据！");
        } catch (Exception e) {
            System.out.println("添加失败！！");
        }

    }

    // 查询
    public static void selectSql(String SelectSql, Connection conn) {
        try {
            ps = conn.prepareStatement(SelectSql);
            // ps.setString(1, "男");
            rs = ps.executeQuery();
            System.out.println("学号		姓名	性别	所在班级");
            while (rs.next()) {
                System.out.println(rs.getString(1) + "	" + rs.getString(2)
                        + "	" + rs.getString(3) + "	" + rs.getString(4));
            }
        } catch (Exception e) {
            System.out.println("查询失败!!");
        }

    }

    // 删除
    public static void deleteSql(String DeleteSql, Connection conn, int sid1) {
        try {
            ps = conn.prepareStatement(DeleteSql);
            ps.setInt(1, sid1);
            int j = ps.executeUpdate();
            System.out.println("有" + j + "条数据被影响,成功的删除" + sid1 + "数据");
        } catch (Exception e) {
            System.out.println("删除失败!!");
        }
    }

    // 更新
    public static void updateSql(String UpdateSql, Connection conn,
            String sname2, int sid2) {
        try {
            ps = conn.prepareStatement(UpdateSql);
            ps.setString(1, sname2);
            ps.setInt(2, sid2);
            int i = ps.executeUpdate();
            System.out.println("有" + i + "条数据被影响,成功更新数据。。");
        } catch (Exception e) {
            System.out.println("更新失败!!");
        }
    }

    public static void start() {
        boolean flag = true;
        Scanner sc = new Scanner(System.in);
        System.out.println("===========欢迎使用t_student表的操作系统===========");
        while (flag) {
            System.out.println("1、添加数据
2、查询数据
3、更新数据
4、删除数据
5、退出");
            System.out.print("请选择您需要的操作:");
            int choice = sc.nextInt();

            switch (choice) {
            case 1:
                // 添加数据
                String sql = "insert into t_student(sid,sname,gender,Classid) values(?,?,?,?)";
                System.out.print("请输入您要添加学号:");
                int sid = sc.nextInt();

                System.out.print("请输入您添加学生的姓名:");
                String sname = sc.next();

                System.out.print("请输入您添加学生的性别:");
                String gender = sc.next();

                System.out.print("请输入您添加学生的班级号:");
                int Classid = sc.nextInt();
                insertSql(sql, conn, sid, sname, gender, Classid);

                System.out.println("添加后的数据为:");
                selectSql("select * from t_student", conn);
                System.out.println();
                System.out.println();
                break;

            case 2:
                // 查询数据
                String SelectSql = "select * from t_student";
                selectSql(SelectSql, conn);
                System.out.println();
                System.out.println();
                break;

            case 3:
                // 更新数据
                String UpdateSql = "update t_student set sname=? where sid=? ";
                System.out.print("请输入要更新姓名的学生学号:");
                int sid2 = sc.nextInt();

                System.out.print("请输入要更新该学号的新姓名:");
                String sname2 = sc.next();
                updateSql(UpdateSql, conn, sname2, sid2);

                System.out.println("更新后的数据为:");
                selectSql("select * from t_student", conn);
                System.out.println();
                System.out.println();
                break;

            case 4:
                // 删除
                String DeleteSql = "delete from t_student where sid=?";
                System.out.print("请输入要删除的学生学号:");
                int sid1 = sc.nextInt();
                deleteSql(DeleteSql, conn, sid1);

                System.out.println("删除后的数据为:");
                selectSql("select * from t_student", conn);
                System.out.println();
                System.out.println();
                break;
            case 5:
                System.out.println("谢谢使用");
                flag = false;
                break;
            default:
                System.out.println("输入有误。。请重新输入");
                System.out.println();
                System.out.println();
                break;
            }
        }

    }

    public static void main(String[] args) {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection(
                    "jdbc:mysql://127.0.0.1:3306/school", "root", "root");
            System.out.println(conn);
            start();

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (ps != null) {
                try {
                    ps.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }

    }

}

运行结果：