@Test
 public void deleteByExample() {
   Criteria example = new Criteria();
   example.put("balance", 123);
   int result = tradeDao.deleteByExample(example);
   assertEquals(1, result);
   int a = tradeDao.countByExample(new Criteria());
   assertEquals(1, a);
 }
 @Test
 public void selectByExample() {
   Criteria example = new Criteria();
   example.put("balance", 123);
   example.setOracleStart(0);
   example.setOracleEnd(10);
   List<Trade> list = tradeDao.selectByExample(example);
   assertEquals("1", list.get(0).getId());
 }
  @Test
  public void updateByExampleSelective() {
    Criteria example = new Criteria();
    example.put("balance", 123);
    Trade trade = new Trade();
    trade.setBalance(new BigDecimal(12));
    trade.setMyaccount("110");
    int result = tradeDao.updateByExampleSelective(trade, example);
    assertEquals(1, result);

    trade = tradeDao.selectByPrimaryKey("1");
    assertEquals("110", trade.getMyaccount());
  }