JDBC

jar包：

mysql-connector-java-5.1.8.jar

概述：

- jdbc是java操作数据库的AP
- 相关包：java.sql.* javax.sql.*

代码：

Code

@Test
public void test() throws Exception {
    //注册驱动
    DriverManager.registerDriver(new com.mysql.jdbc.Driver());

    //获取连接对象
    Connection con = DriverManager.getConnection("jdbc:mysql://10.211.55.6:3306/jdbc",
            "machine","4869");

    //获取操作sql的Statement
    Statement st = con.createStatement();

    //执行sql语句，得到Statement
    ResultSet rs = st.executeQuery("SELECT * FROM USER");

    //操作结果集，得到数据
    while(rs.next()){
        System.out.println("id: "+rs.getInt("id")+
                "\tusername: "+rs.getString("username")+
                "\tpassword: "+rs.getString(“password")
        );
    }

    //关闭资源
    rs.close();
    st.close();
    con.close();
}

PreparedStatement:处理sql注入

Code

//获取PreparedStatement
PreparedStatement ps = con.prepareStatement(
        "INSERT INTO USER VALUES(NULL,?,?,?)");

//设置字段:第一个？为1，类推
ps.setString(1,"machine");
ps.setString(2,"123");
ps.setString(3,"machine@163.com");

//执行
ps.executeUpdate();
//若是查找(select)，则ps.executeQuery(), 返回ResultSet结果集

Sql:

Code

CREATE TABLE USER( 
    id INT PRIMARY KEY AUTO_INCREMENT, 
    username VARCHAR(20) , 
    password VARCHAR(20) , 
    email VARCHAR(40) 
);

INSERT INTO USER VALUES(NULL,'tom','123','tom@163.com'); 
INSERT INTO USER VALUES(NULL,'fox','456','fox@163.com');
INSERT INTO USER VALUES(NULL,'james','789','james@163.com');

select * from USER