java学习笔记--JDBC实例

使用的数据库：

mysql> use xiao;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+----------------+
| Tables_in_xiao |
+----------------+
| students       |
+----------------+
1 row in set (0.00 sec)

mysql> desc students;
+-------+---------------------+------+-----+---------+----------------+
| Field | Type                | Null | Key | Default | Extra          |
+-------+---------------------+------+-----+---------+----------------+
| id    | int(10) unsigned    | NO   | PRI | NULL    | auto_increment |
| name  | char(8)             | NO   |     | NULL    |                |
| sex   | char(4)             | NO   |     | NULL    |                |
| age   | tinyint(3) unsigned | NO   |     | NULL    |                |
| tel   | char(13)            | YES  |     | -       |                |
+-------+---------------------+------+-----+---------+----------------+
5 rows in set (0.04 sec)

mysql> select * from students;
+----+---------+-----+-----+-------------+
| id | name    | sex | age | tel         |
+----+---------+-----+-----+-------------+
|  1 | xiaoye  | m   |  31 | 15711580618 |
|  2 | heilong | m   |  31 | 13313812130 |
|  3 | baba    | m   |  60 | 13313818223 |
|  4 | xiaoye  | m   |  30 | 17750311103 |
+----+---------+-----+-----+-------------+
4 rows in set (0.00 sec)

mysql>

java例子：

import com.mysql.jdbc.Driver;

import java.sql.*;

public class JDBCTest {
    public static void main(String[] args) {
        Connection connection = new JDBCTest().getConnection(); //调用getConnection方法
        try {
 Statement statement = connection.createStatement();
 ResultSet resultSet = statement.executeQuery("select * from students;"); //executeQuery executeUpdate execute 的区别
 while(resultSet.next()) {　　//循环resultSet，调用next（）移动至第一条数据，没有hasnext（）方法；
 int id = resultSet.getInt(1);
 String name = resultSet.getString(2);
 String sex = resultSet.getString(3);
 int age = resultSet.getInt(4);
 String tel = resultSet.getString(5);
 System.out.println(id + " " + name + " " + sex + " " + age + " " + tel + ";");
 }

 } catch (SQLException e) {
 e.printStackTrace();
 }finally {
 try {
 connection.close();
 } catch (SQLException e) {
 e.printStackTrace();
 }
 }

 }

 public Connection getConnection() {
 try {
 Class.forName("com.mysql.jdbc.Driver");　　//加载驱动
 return DriverManager.getConnection("jdbc:mysql://localhost:3306/xiao","root","×××××××"); //链接数据库 注意ruturn
 } catch (Exception e) {
 e.printStackTrace();
 }
 return null;　　//return
 }
}