最新学习所得
eclipse平台中连接数据库，没想到这么简单！总共分几步：
1. 下载mysql-connector-java-5.1.8.jar，并加到eclipse工程中；
2. 用吧！用得过程分几步：
- connection：可完成用户名，密码，数据库的连接，可创建statement来实现sql操作,
- statement：可执行sql语句,
- resultset：对statement执行sql后，返回的记录进行处理，其类下有rs.getString(),getFloat()等等函数；使用结束后，三者都要close()
具体示例如下所示：
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
public class DBtest {
public static void main(String agrs[]) {
String driver = "com.mysql.jdbc.Driver";
try {
Connection con;
Statement stmt;
ResultSet rs;
Class.forName(driver);
DriverManager.registerDriver(new com.mysql.jdbc.Driver());
String dbUrl = "jdbc:mysql://localhost:3306/bookdb?useUnicode=true&characterEncoding=gb2312";
String user = "root";
String password = "";
con = DriverManager.getConnection(dbUrl, user, password);
//与数据库建立连接
stmt = con.createStatement();
String sql = "select id,name,title,price from books";
stmt.executeUpdate("insert into books (id,name,title,price) values ('123','tom','tomcat bible',44.5)");
rs = stmt.executeQuery(sql);
//con 創建stmt,stmt执行sql语句，将查询结果返回给rs，由循环处理rs获得的字段
while (rs.next()) {
String col1 = rs.getString("id");
String col2 = rs.getString("name");
String col3 = rs.getString("title");
float col4 = rs.getFloat("price");
System.out.println(col1+"\t"+col2+"\t"+col3+"\t"+col4);
}
stmt.executeUpdate("delete from books where id = '123'");
//stmt执行sql语句
rs.close();//关闭rs,con,stmt
stmt.close();
con.close();
} catch (Exception e) {
System.out.println("无法加载驱动程序" + driver);
}
}
}