阜蒙县建设镇官方网站,响应式网站开发设计师,电子商务网站建设与维护项目五,网站视频外链怎么做使用软件#xff1a;mysql、eclipse链接步骤#xff1a;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#xff0c;关闭顺序一般是(setresult --- statement …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;78 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 stconn.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Overridepublic 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Overridepublic 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Overridepublic 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Overridepublic 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Overridepublic 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;}}内容来源于网络如有侵权请私信删除
