### DBUtils完成轉賬 ~~~ Connection connection = null; try { QueryRunner queryRunner = new QueryRunner(); //得使用這種構造函數,因為傳入連接池的我們不能保證執行SQL語句的是同一個連接.  connection = C3P0Utils.getConnection(); connection.setAutoCommit(false); int tom = queryRunner.update(connection, "update account set money = money - ? where name = ?", 1000, "tom"); int jack = queryRunner.update(connection, "update account set money = money + ? where name = ?", 1000, "jack"); System.out.println(1 / 0); connection.commit(); if (tom > 0 && jack > 0) { System.out.println("轉賬成功"); } } catch (SQLException e) { try { connection.rollback(); } catch (SQLException sql) { sql.printStackTrace(); } e.printStackTrace(); } finally { try { connection.close(); } catch (SQLException e) { e.printStackTrace(); } } ~~~