java JDBC数据库操作

以前的代码，现在重新贴出来。。

1 Datebase.java  数据库的基本连接，下面几个java文件都用到，所以写成一个java文件。

import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.SQLException;public class Datebase {public static Connection openconn() {Connection conn = null;try {Class.forName("com.mysql.jdbc.Driver");String url = "jdbc:mysql://localhost/test?characterEncoding=UTF-8";String user = "root";String password = "";conn = DriverManager.getConnection(url, user, password);if (conn != null) {System.out.println("连接成功");}} catch (SQLException e) {System.out.println("连接失败");} catch (ClassNotFoundException e) {System.out.println("驱动程序导入失败");}return conn;}public static void closeconn(PreparedStatement ptml, Connection conn) {if (ptml != null) {try {ptml.close();if (conn != null) {conn.close();}System.out.println("数据库关闭成功");} catch (SQLException e) {System.out.println("关闭失败");}}}public static void main(String[] args) {openconn();}}

Demo1.java 数据库的添加操作

import java.sql.Connection;import java.sql.PreparedStatement;public class Demo1 {private static Datebase conn = new Datebase();// private static Student stu = new Student();public static int add(Student stu) throws Exception {Connection conn = Datebase.openconn();String sql = "insert into gdmec values(?,?,?,?)";PreparedStatement ptml = conn.prepareStatement(sql);ptml.setString(1, stu.getId());ptml.setString(2, stu.getName());ptml.setInt(3, stu.getAge());ptml.setString(4, stu.getClassName());int result = ptml.executeUpdate();Datebase.closeconn(ptml,conn);return result;}public static void main(String[] args) throws Exception {Student stu = new Student("as", "ss", 12, "55");int result = add(stu);if (result == 1) {System.out.println("添加成功!");} else {System.out.println("添加失败!");}}}

Demo2.java 数据库修改操作

import java.sql.Connection;import java.sql.PreparedStatement;public class Demo2 {private static Datebase conn = new Datebase();public static int update(Student stu) throws Exception {Connection conn = Datebase.openconn();String sql = "update gdmec set id=?,name=?,age=?,className=? where id='as'";PreparedStatement ptml = conn.prepareStatement(sql);ptml.setString(1, stu.getId());ptml.setString(2, stu.getName());ptml.setInt(3, stu.getAge());ptml.setString(4, stu.getClassName());//ptml.setString(5, stu.getId());int result=ptml.executeUpdate();Datebase.closeconn(ptml,conn);return result;}public static void main(String[] args) throws Exception {Student stu = new Student("11", "ss", 12, "66");int result = update(stu);if (result >= 1) {System.out.println("修改成功!");} else {System.out.println("修改失败!");}}}

Demo3.jvav 数据库删除操作

import java.sql.Connection;import java.sql.PreparedStatement;public class Demo3 {private static Datebase conn = new Datebase();public static int delete(String id)throws Exception{Connection conn = Datebase.openconn();String sql = "delete from gdmec where id=?";PreparedStatement ptml = conn.prepareStatement(sql);ptml.setString(1, id);int result = ptml.executeUpdate();Datebase.closeconn(ptml,conn);return result;}public static void main(String[] args)  throws Exception{int result = delete("11");if (result >= 1) {System.out.println("删除成功!");} else {System.out.println("删除失败!");}}}

Demo4.java 数据库查询操作

import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.util.ArrayList;import java.util.List;public class Demo4 {private static Datebase conn = new Datebase();public static List<Student> select() throws Exception {List<Student> list = new ArrayList<Student>();Connection conn = Datebase.openconn();String sql = "select * from gdmec";PreparedStatement ptml = conn.prepareStatement(sql);ResultSet rs = ptml.executeQuery();while (rs.next()) {String id = rs.getString("id");String name = rs.getString("name");int age = rs.getInt("age");String className = rs.getString("className");Student stu = new Student(id, name, age, className);list.add(stu);}return list;}public static void main(String[] args) throws Exception {List<Student> list = select();for (Student student : list) {System.out.println(list);}}}

Student.java  student类的基本信息

public class Student {private String id;private String name;private int age;private String className;public String getId() {return id;}public void setId(String id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getClassName() {return className;}public void setClassName(String className) {this.className = className;}public Student() {super();// TODO Auto-generated constructor stub}public Student(String id, String name, int age, String className) {super();this.id = id;this.name = name;this.age = age;this.className = className;}@Overridepublic String toString() {return "["+this.id + "," + this.name + ","+ this.age + ","+ this.className+"]";}}

jar包 mysql-connector-java-5.1.19-bin.jar