JDBC | 第一章: 快速开始使用JDBC连接Mysql数据库之简单CRUD

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开始使用基于java的 JDBC 技术来连接mysql进行msyql数据库简单的 CRUD 操作

下载对应mysql驱动包

这里我创建maven项目基于maven下载

<!--mysql 驱动-->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.21</version>
    </dependency>
    <!---->

连接数据库

/*
 * jdbc:mysql:  是指JDBC连接方式；
 *127.0.0.1:       是指你的本机地址；
 * 3306               SQL数据库的端口号；
 * mysql              就是你要连接的数据库的名字。
 * characterEncoding     指定数据库连接的编码方式
 * com.mysql.jdbc.Driver  注册数据库驱动 过时
 * com.mysql.cj.jdbc.Driver  新的数据库驱动
 */
       public Connection getConnection() {

        //mysql 连接url
        String url = "jdbc:mysql://localhost:3306/kenx_test?characterEncoding=utf-8";
        //数据库用户名
        String userName = "root";
        //数据库密码
        String passWord = "root";
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");  //注册数据库驱动
            Connection conn = DriverManager.getConnection(url, userName, passWord); //获取数据连接
            System.out.println("数据库连接成功");
            return conn;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

进行数据添加操作

public int ins() {
        Connection connection = null;
        Statement statement = null;
        String sql = "";
        try {
            //获取数据连接
            connection = getConnection();
            //获取发送sql指令执行sql对象
            statement = connection.createStatement();
            StringBuffer sbf = new StringBuffer("insert into user (id, name, age, email, manager_id, create_time)");
            String id = String.valueOf(System.currentTimeMillis());
            Timestamp dateTime = Timestamp.valueOf(DateUtil.now());

            sbf.append(" values (" + id + ",'kenx',24,'17521197955@163.com',155065178165505,'" + dateTime + "')");
            sql = sbf.toString();
            System.out.println("执行sql" + sql);
            //执行成功返回1
            int success = statement.executeUpdate(sql);
            return success;
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        }finally {
            //执行完数据库操作后记得关闭数据库连接资源
            try{

                statement.close();
                connection.close();

            }catch (SQLException e){
                e.printStackTrace();
            }

        }

    }

进行数据库的查询操作

public void select() {
        Connection connection = null;
        Statement statement = null;
        ResultSet rs = null;
        String sql = "select * from user limit 0,1";
        try {
            //获取数据连接
            connection = getConnection();
            //获取发送sql指令执行sql对象
            statement = connection.createStatement();
            //返回查询结果集用于保存数据库查询内容
            rs = statement.executeQuery(sql);
            //遍历结果集拿到数据
            while (rs.next()) {
                System.out.println("id" + "\t" + rs.getString("id"));
                System.out.println("name" + "\t" + rs.getString("name"));
                System.out.println("age" + "\t" + rs.getString("age"));
                System.out.println("email" + "\t" + rs.getString("email"));
                System.out.println("manager_id" + "\t" + rs.getString("manager_id"));
                System.out.println("create_time" + "\t" + rs.getString("create_time"));
            }
        } catch (Exception e) {
            e.printStackTrace();
        }finally {
            //执行完数据库操作后记得关闭数据库连接资源
            try{
                rs.close();
                statement.close();
                connection.close();

            }catch (SQLException e){
                e.printStackTrace();
            }

        }
    }

进行数据库更新操作

public int update() {
        Connection connection = null;
        Statement statement = null;
        String sql = "update user\n" +
                "set manager_id =155065512602445\n" +
                "where id=1597890374878";
        try {
            //获取数据连接
            connection = getConnection();
            //获取发送sql指令执行sql对象
            statement = connection.createStatement();
            //更新成功返回1
            int success = statement.executeUpdate(sql);
            return success;
        } catch (Exception e) {
            e.printStackTrace();
            return 0;

        }finally {
            //执行完数据库操作后记得关闭数据库连接资源
            try{
                statement.close();
                connection.close();

            }catch (SQLException e){
                e.printStackTrace();
            }

        }

    }

进行数据库删除操作

public int del(){
        Connection connection = null;
        Statement statement = null;
        String sql = "delete from user where id='1597890374878'";
        try {
            //获取数据连接
            connection = getConnection();
            //获取发送sql指令执行sql对象
            statement = connection.createStatement();
            //删除成功返回1
            int success = statement.executeUpdate(sql);
            return success;
        } catch (Exception e) {
            e.printStackTrace();
            return 0;

        }finally {
            //执行完数据库操作后记得关闭数据库连接资源
            try{
                statement.close();
                connection.close();

            }catch (SQLException e){
                e.printStackTrace();
            }

        }
    }

完整项目案例
点击这里 github

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原文链接：https://www.cnblogs.com/kenx/p/13534065.html

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