c3p0学习
1.ideal 启动web项目时要将数据库驱动包放入tomcat 的lib目录下
2.启动事务。。。
3.jdbc事务
1 package main.com.cn.pojo; 2 3 import java.sql.*; 4 5 public class JdbcTest { 6 public static final String URL = "jdbc:mysql://localhost:3306/mydb2"; 7 public static final String USER = "root"; 8 public static final String PASSWORD = "root"; 9 public static void main(String[] args) { 10 Connection conn = null; 11 try { 12 //1.加载驱动程序 13 Class.forName("com.mysql.jdbc.Driver"); 14 //2. 获得数据库连接 15 conn = DriverManager.getConnection(URL, USER, PASSWORD); 16 conn.setAutoCommit(false); 17 //3.操作数据库，实现增删改查 18 String sql1 = "update account set money = money -? where name = ?"; 19 String sql2 = "update account set money = money +? where name = ?"; 20 PreparedStatement ps = conn.prepareStatement(sql1); 21 ps.setInt(1,100); 22 ps.setString(2,"reba"); 23 ps.executeUpdate(); 24 PreparedStatement ps2 = conn.prepareStatement(sql2); 25 ps2.setInt(1,100); 26 ps2.setString(2,"baby1"); 27 ps2.executeUpdate(); 28 int i = 1/0; 29 conn.commit(); 30 } catch (Exception e) { 31 try { 32 conn.rollback(); 33 } catch (SQLException e1) { 34 } 35 } 36 } 37 }
