使用jdbc对MySQL数据库进行增删改查

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使用jdbc对数据库进行增删改查操作

//学生类public class Student {    //学生的属性    private static String id;    private static String name;    private static String age;    private static String grade;    private static String academy;    private static String specialty;    public Student(){    }    public static String getId() {        return id;    }    public static void setId(String id) {        Student.id = id;    }    public static String getName() {        return name;    }    public static void setName(String name) {        Student.name = name;    }    public static String getAge() {        return age;    }    public static void setAge(String age) {        Student.age = age;    }    public static String getGrade() {        return grade;    }    public static void setGrade(String grade) {        Student.grade = grade;    }    public static String getAcademy() {        return academy;    }    public static void setAcademy(String academy) {        Student.academy = academy;    }    public static String getSpecialty() {        return specialty;    }    public static void setSpecialty(String specialty) {        Student.specialty = specialty;    }}

//连接mysql数据库的类import java.sql.Connection;import java.sql.DriverManager;import java.sql.Statement;public class ConnectMySQL {    private static final String Url = "jdbc:mysql://localhost:3306/student";  //student是数据库名称    private static final String User="root";    private static final String Password="";    public ConnectMySQL(){    }    public Statement Connect() throws Exception{        //1.加载驱动程序        Class.forName("com.mysql.jdbc.Driver");        //获取连接        Connection conn = DriverManager.getConnection(Url, User, Password);         //操作数据库        Statement stm = conn.createStatement();        return stm;    }}

//添加学生类import java.sql.Connection;import java.sql.Statement;import java.util.Scanner;public class AddStudent {    /*     * 添加学生的类     */    public AddStudent() throws Exception{        Student stu = new Student();  //构建学生类实例        Statement stm = new ConnectMySQL().Connect(); //连接数据库，不用特意New一个对象出来        SearchStudent sech = new SearchStudent();  //查找学生是否已经存在的情况        //用户输入学生学号        System.out.println("请输入学生学号");        Scanner input = new Scanner(System.in);  //输入，接受之后存储到setter中，不然后来的会覆盖掉        String id = input.next();        stu.setId(id);        if(sech.search(id) == 1){            //原方法中已经输出了相关的提示        }else{        //输入学生姓名        System.out.println("请输入学生名字");        String name = input.next();        stu.setName(name);        //输入学生年龄        System.out.println("请输入学生年龄");        String age = input.next();        stu.setAge(age);        //输入学生年级        System.out.println("请输入学生年级");        String grade = input.next();        stu.setGrade(grade);        //输入学生学院        System.out.println("请输入学生学院");        String academy = input.next();        stu.setAcademy(academy);        //输入学生专业        System.out.println("请输入学生专业");        String specialty = input.next();        stu.setSpecialty(specialty);        //显示录入信息        System.out.println("录入信息如下:");        System.out.println("学号:"+stu.getId()+"  姓名:"+stu.getName()+"  年龄:"+stu.getAge()            +"  年级:"+stu.getGrade()+"  学院:"+stu.getAcademy()+"  专业:"+stu.getSpecialty());        System.out.println("请确认是否录入:1.确认\t2.取消"); //没有对非法字符进行处理        int choose = input.nextInt();        if(choose == 1){        String sql = "insert into stu values('"+stu.getId()+"','"+stu.getName()+"',"                + "'"+stu.getAge()+"','"+stu.getGrade()+"',"                + "'"+stu.getAcademy()+"','"+stu.getSpecialty()+"');";            stm.execute(sql);            System.out.println("OK");        }        }    } }

//删除学生类import java.sql.ResultSet;import java.sql.Statement;import java.util.Scanner;public class DeleteStudent {    public DeleteStudent() throws Exception{        Statement stm = new ConnectMySQL().Connect();        SearchStudent sech = new SearchStudent();//查找        System.out.println("请输入您要删除的学生学号:");        Scanner input = new Scanner(System.in);        String did = input.next();        //sql查询语句        if(sech.search(did) == 0){        }else{            String sql = "delete from stu where id = '"+did+"'";            stm.execute(sql);            System.out.println("删除成功!");        }           }}

//查询学生类import java.sql.ResultSet;import java.sql.Statement;public class SearchStudent {    public SearchStudent(){    }    /*     * 判断学生是否存在     */    public static int search(String id) throws Exception{        Statement stm = new ConnectMySQL().Connect();        //sql查询语句        String sql = "select * from stu where id = '"+id+"'";        ResultSet rst = stm.executeQuery(sql);        if(rst.next()){            System.out.println("该学生存在！");            return 1;        }else{            System.out.println("该学生不存在,可添加");            return 0;        }    }}

//打印学生类import java.sql.ResultSet;import java.sql.Statement;public class Print {    public Print() throws Exception{        Statement stm = new ConnectMySQL().Connect();        String sql = "select * from stu";        ResultSet res = stm.executeQuery(sql);        while(res.next()){        System.out.println("学号:"+res.getString(1)+"  姓名:"+res.getString(2)+"  年龄:"+res.getString(3)+""        + "  年级:"+res.getString(4)+"  学院:"+res.getString(5)+"  专业:"+res.getString(6));        System.out.println("------------------------------------------------------------------------");        }       }   }

//主方法import java.util.Scanner;public class Main {    public static int k=1;  //用来结束循环的标记    public static void main(String[] args) throws Exception {        System.out.println("----------欢迎进入学生信息管理界面----------");        System.out.println("     -----1.打印所有学生信息------");        System.out.println("     -----2.查找学生信息---------");        System.out.println("     -----3.增加学生信息---------");        System.out.println("     -----4.删除学生信息---------");        System.out.println("     -----5.退出界面------------");        while(k!=0){        Scanner input1 = new Scanner(System.in);        int i = input1.nextInt();           switch(i){        case 1:new Print();break;        case 2:System.out.println("请输入学生学号:");        String id = input1.next();        new SearchStudent().search(id);        break;        case 3:new AddStudent();break;        case 4:new DeleteStudent();break;        case 5:k=0;break;        }        }    }}

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