通过jdbc连接数据库

1、导入相关数据库的jar包

<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.0.7</version>
</dependency>

2、代码编写

2.1、查询

由于个人感觉在写随笔的时候，代码中简单的步骤添加try catch会看起来不清晰，故没有添加。在实际中还是需要的。

public static void main( String[] args ) throws ClassNotFoundException, SQLException {
	// 数据库连接地址
    String url = "jdbc:mysql://localhost:3306/ssmbuild?useUnicode=true&characterEncoding=utf-8";
    String user = "root";
    String password = "123456";

    // 1、加载驱动
    Class.forName("com.mysql.jdbc.Driver");
    // 2、获取连接
    Connection connection = DriverManager.getConnection(url, user, password);
    // 3、编写SQL语句
    String sql = "SELECT * FROM `ssmbuild`.`books`";
    // 4、创建prepareStatement对象
    PreparedStatement preparedStatement = connection.prepareStatement(sql);
    // 5、使用prepareStatement对象执行SQL语句
    ResultSet resultSet = preparedStatement.executeQuery();
    // 6、遍历返回的结果集
    while (resultSet.next()){
        // 根据数据库创建对应的实体类！
        Book book = new Book();
        // 把查询到的结果封装到实体类！
        book.setBookID(resultSet.getInt("bookID"));
        book.setBookName(resultSet.getString("bookName"));
        book.setBookCounts(resultSet.getInt("bookCounts"));
        book.setDetail(resultSet.getString("detail"));
        System.out.println(book.toString());
    }

    // 7、关闭资源，先开后关
    resultSet.close();
    preparedStatement.close();
    connection.close();
    }

2.2、增加

public static void main( String[] args ) throws ClassNotFoundException, SQLException {

        String url = "jdbc:mysql://localhost:3306/ssmbuild?useUnicode=true&characterEncoding=utf-8";
        String user = "root";
        String password = "123456";

        // 1、加载驱动
        Class.forName("com.mysql.jdbc.Driver");
        // 2、获取连接
        Connection connection = DriverManager.getConnection(url, user, password);
        // 3、编写SQL语句
        String sql = "INSERT INTO `ssmbuild`.`books` (`bookName`, `bookCounts`, `detail`) VALUES (?, ?, ?)";
        // 4、创建prepareStatement对象
        PreparedStatement preparedStatement = connection.prepareStatement(sql);
    	// 预编译对象，我们需要把？号替换
        preparedStatement.setString(1,"C");
        preparedStatement.setInt(2,20);
        preparedStatement.setString(3,"从零开始");
        // 5、使用prepareStatement对象执行SQL语句
        int i = preparedStatement.executeUpdate();

        if (i>0){
            System.out.println("数据插入成功！");
        }else {
            System.out.println("失败！");
        }

        // 6、关闭资源，先开后关
        preparedStatement.close();
        connection.close();
    }

	// 增删改都一样，换一下SQL语句就可以！

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