第一个JDBC——Toy procedure(玩具程序)
import java.sql.*;
public class TestJDBC {
/**
* @param args */ public static void main(String[] args) throws Exception { // TODO Auto-generated method stub Class.forName("oracle.jdbc.driver.OracleDriver");//这个Class类的方法,相当于直接new出了一个实例 // new oracle.jdbc.driver.OracleDriver();和上面的没优劣之分//实例好了 自动向DriverMangager注册 Connection conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:ORCL", "SCOTT", "mm");//第一个参数是连接字符串 Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery("select * from dept"); while(rs.next()) { System.out.println(rs.getString("deptno"));//当成字符串拿出来也可以 System.out.println(rs.getInt("deptno"));//只要能转换成int就能拿出来 } rs.close();//后打开的先关哦 stmt.close(); conn.close(); } }
稍微完善它一下后 :
import java.sql.*;
public class TestJDBC {
/**
* @param args */ public static void main(String[] args) { // TODO Auto-generated method stub ResultSet rs = null; Statement stmt = null; Connection conn = null; try { Class.forName("oracle.jdbc.driver.OracleDriver");//这个Class类的方法,相当于直接new出了一个实例 // new oracle.jdbc.driver.OracleDriver();和上面的没优劣之分//实例好了 自动向DriverMangager注册 conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:ORCL", "SCOTT", "mm");//第一个参数是连接字符串 stmt = conn.createStatement(); rs = stmt.executeQuery("select * from dept"); while(rs.next()) { System.out.println(rs.getString("deptno"));//当成字符串拿出来也可以 System.out.println(rs.getInt("deptno"));//只要能转换成int就能拿出来 } } catch(ClassNotFoundException e) { System.out.println("找不到相关的驱动哦"); e.printStackTrace(); } catch(SQLException e) { e.printStackTrace(); } finally { try { if(rs!=null) {//没有初始化肯定报错哦,所以判断下 rs.close();//后打开的先关哦 rs = null;//设为空后,垃圾收集器随时可以收集回去了(稍稍好点呢) } if(stmt!=null) { stmt.close(); stmt = null; } if(conn!=null) { conn.close(); conn = null; } } catch(SQLException e) { e.printStackTrace(); } } } }
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