JDBC讲解

1.JDBC API:Java DataBase Connectivity(java数据库访问技术)
a.Connection conn=DriverManager.getConnection(url,"root","passwod")         //修通道 建立连接
b.PreparedStatement ps=conn.preparsedStatement(sql)        //货车 语句
    eg,I.sql = "select *from student whrer sname=?";
c.ResultSet rs=ps.executeQuery();        //显示结果

新建Web项目、包、类。写入驱动的三个方法。
Connection conn=null;
PerpareStatement ps=null;
ResultSet rs=null;
String sql="SELECT * FROM book1";
String url="jdbc:mysql://localhost:3306/demo";

conn=DriverManager.getConnection(url,"user","password");
ps = conn.prepareStatment(sql);
rs = ps.executeQuery();         //执行查询

while(rs.next()){
        String sno=rs.getString(1);
        System.out.println(sno);
        System.out.println(re.getString(1));
        System.out.println(re.getString(2));
        System.out.println(re.getString(3));
        System.out.println(re.getString(4));
        System.out.println(re.getInt(5));
}
        rs.close();
        ps.close();
        conn.close();
开始时倒入jar包：Class.Class.forName("com.mysql.Drive");
调整异常：close之前全部包裹进一个异常
close相关的接在其后的finally里。

下面附上实测代码：
package jdbc;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import javax.servlet.jsp.jstl.sql.Result;

public class JDBC {

public static void main(String[] args) {

TODO Auto-generated method stub

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs = null;

String url = jdbcmysqllocalhost3306bookstor;  数据库位置  直接跟数据库名称

String sql = SELECT  FROM student;  SQL语句

try {  加载驱动的异常

Class.forName(com.mysql.jdbc.Driver);

conn = DriverManager.getConnection(url, root, 123456);

ps = conn.prepareStatement(sql);

rs = ps.executeQuery();  获得数据

while (rs.next()) {

System.out.println(rs.getString(1));

System.out.println(rs.getString(2));

System.out.println(rs.getString(3));

System.out.println(rs.getString(4));

System.out.println(rs.getInt(5));

}

} catch (ClassNotFoundException e) {

TODO Auto-generated catch block

e.printStackTrace();

} catch (SQLException e) {

TODO Auto-generated catch block

e.printStackTrace();

} finally {

try {

rs.close();

ps.close();

conn.close();

} catch (SQLException e) {

TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}