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  • jdbc -- 001 -- 一般方式创建数据库连接(oracle/mysql)

    连接数据库步骤:
    1. 注册驱动(只做一次)
    2. 建立连接(Connection)
    3. 创建执行SQL的语句(Statement)
    4. 执行语句
    5. 处理执行结果(ResultSet)
    6. 释放资源
    举例:
    public
    void connectionOracle() throws SQLException{ Connection conn = null; // 数据库连接 PreparedStatement ps = null; // 预编译语句对象 ResultSet rs = null; // 结果集对象 try { // 注册(加载)Oracle驱动 Class.forName("oracle.jdbc.driver.OracleDriver");
    // Class.forName("com.mysql.jdbc.Driver");
    注册(加载)mysql驱动
    String url = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
    //String url = "jdbc:mysql://127.0.0.1:3306/mybatis";
    //String url = "jdbc:mysql://localhost:3306/mybatis";
    String user
    = "scott"; String password = "tiger"; conn = DriverManager.getConnection(url, user, password); String sql = "select ename from emp where job ='CLERK'"; ps = conn.prepareStatement(sql); rs = ps.executeQuery(); while(rs.next()){ System.out.println("ename is : " + rs.getString("ename")); } System.out.println("End@@@"); } catch (ClassNotFoundException e) { e.printStackTrace(); }finally {
    try {    if (rs != null) {rs.close();}}
    finally {
    try {if (ps != null) {ps.close();}}
    finally {if (conn != null) {conn.close();}
    }
    }
    }
    }
     如果sql="select count(*) from items";
     则使用时
    while(rs.next()){
      System.out.println(rs.getInt(1));
    }
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  • 原文地址:https://www.cnblogs.com/ysloong/p/6381645.html
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