使用软件：mysql、eclipse

链接步骤：

1.注册驱动

2.创建一个连接对象

3.写sql语句

4.执行sql语句并返回一个结果或者结果集

5.关闭链接(一般就是connection、statement、setresult)这三个连接对象，关闭顺序一般是(setresult    --->  statement  -->  setresult  )

一、直接连接方法：(这种方法就是讲sql语句和结果所有的步骤写在一起) 不建议使用该方法

1 public static voidmain(String[] args) {2 String url = "jdbc:mysql://localhost:3306/students";3 String user = "root";4 String password = "admin";5 Connection conn = null;6 Statement st = null;7

8 try{9 //1. 注册驱动

10 Class.forName("com.mysql.jdbc.Driver");11 //2. 创建一个链接对象

12 conn =DriverManager.getConnection(url,user,password);13 //3. 创建一个sql语句的发送命令对象

14 String sql = "insert into student values('2001','Tom','20','7000')";15 st=conn.createStatement();16 //4. 执行sql语句，拿到查询的结果集对象

17 st.executeQuery(sql);20 } catch(Exception e) {21 e.printStackTrace();22 }finally{23 //5. 关闭链接 ，命令对象 ，结果集

24 if(st != null) {25 try{26 st.close();27 } catch(Exception e) {28 e.printStackTrace();29 }30 }31 if(conn != null) {32 try{33 conn.close();34 } catch(Exception e) {35 e.printStackTrace();36 }37 }38 }

二、建立工具类方法，将必要的几步写一个类，使用的时候直接调用(建议使用)

1.注册驱动、创建连接对象、关闭资源    这三部一般可以写一个类，由于写sql语句和执行sql语句的结果不一致，所以可以将其在用到的时候在写

2.一般写工具类都是写成静态方法，以方便调用

//这是工具类：

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

public class JdbcUtils {

private static String driverName = "com.mysql.jdbc.Driver";

private static String url = "jdbc:mysql://localhost:3306/student_achievement_system";

private static String user = "root";

private static String password = "admin";

/**

* 链接数据库

*/

static {

try {

Class.forName(JdbcUtils.driverName);

} catch (Exception e) {

e.printStackTrace();

}

}

/**

* 获取链接对象connection

* @return

*/

public static Connection getConnection() {

try {

return DriverManager.getConnection(JdbcUtils.url, JdbcUtils.user, JdbcUtils.password);

} catch (Exception e) {

e.printStackTrace();

}

return null;

}

/**

* 关闭资源

* @param conn

* @param st

* @param rs

*/

public static void close(Connection conn,Statement st,ResultSet rs) {

if(rs != null) {

try {

rs.close();

} catch (Exception e) {

e.printStackTrace();

}

}

if(st != null) {

try {

st.close();

} catch (Exception e) {

e.printStackTrace();

}

}

if(conn != null) {

try {

conn.close();

} catch (Exception e) {

e.printStackTrace();

}

}

}

}

//这是对数据库的基本操作类

// 增加、删除、更新、查找一条、查找所有的方法

public class StudentsDaoImpl implements IStudentsDao {

//增加

@Override

public int save(Students student) {

Connection conn = null;

PreparedStatement ps = null;

try {

conn = JdbcUtils.getConnection();

String sql = "insert into students values(?,?,?,?,?,?)";

ps = conn.prepareStatement(sql);

ps.setInt(1, student.getStudentId());

ps.setString(2, student.getStudentName());

ps.setString(3, student.getSex());

ps.setString(4, student.getPhoneNo());

ps.setString(5, student.getAddress());

ps.setDate(6, (Date) student.getBirthday());

int row = ps.executeUpdate();

return row;

} catch (Exception e) {

e.printStackTrace();

}finally {

JdbcUtils.close(conn, ps, null);

}

return 0;

}

//删除

@Override

public int delete(int studentId) {

Connection conn = null;

PreparedStatement ps = null;

try {

conn = JdbcUtils.getConnection();

String sql = "delete from students where studentId=?";

ps = conn.prepareStatement(sql);

ps.setInt(1, studentId);

int row = ps.executeUpdate();

return row;

} catch (Exception e) {

e.printStackTrace();

}finally {

JdbcUtils.close(conn, ps, null);

}

return 0;

}

//更新

@Override

public int update(int studentId, Students student) {

Connection conn = null;

PreparedStatement ps = null;

try {

conn = JdbcUtils.getConnection();

String sql = "update students set studentName=?,sex=?,phoneNo=?,address=?,birthday=? where studentId=?";

ps = conn.prepareStatement(sql);

ps.setString(1, student.getStudentName());

ps.setString(2, student.getSex());

ps.setString(3, student.getPhoneNo());

ps.setString(4, student.getAddress());

ps.setDate(5, ((Date) student.getBirthday()));

ps.setInt(6, studentId);

int row = ps.executeUpdate();

return row;

} catch (Exception e) {

e.printStackTrace();

}finally {

JdbcUtils.close(conn, ps, null);

}

return 0;

}

//查找一条数据

@Override

public Students getByStudentId(int studentId) {

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs = null;

try {

conn = JdbcUtils.getConnection();

String sql = "select * from students where studentId=?";

ps = conn.prepareStatement(sql);

ps.setInt(1, studentId);

rs = ps.executeQuery();

if(rs.next()) {

Students student = new Students();

student.setStudentId(rs.getInt("studentId"));

student.setStudentName(rs.getString("studentName"));

student.setSex(rs.getString("sex"));

student.setPhoneNo(rs.getString("phoneNo"));

student.setAddress(rs.getString("address"));

student.setBirthday(rs.getDate("birthday"));

return student;

}

} catch (Exception e) {

e.printStackTrace();

}finally {

JdbcUtils.close(conn, ps, rs);

}

return null;

}

//查找所有数据

@Override

public List getAll() {

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs = null;

try {

conn = JdbcUtils.getConnection();

String sql = "select * from students";

ps = conn.prepareStatement(sql);

rs = ps.executeQuery();

List studentsList = new ArrayList<>();

while(rs.next()) {

Students student = new Students();

student.setStudentId(rs.getInt("studentId"));

student.setStudentName(rs.getString("studentName"));

student.setSex(rs.getString("sex"));

student.setPhoneNo(rs.getString("phoneNo"));

student.setAddress(rs.getString("address"));

student.setBirthday(rs.getDate("birthday"));

studentsList.add(student);

}

return studentsList;

} catch (Exception e) {

e.printStackTrace();

}finally {

JdbcUtils.close(conn, ps, rs);

}

return null;

}

}