##Example example = new ##Example();  
    example.setOrderByClause("欄位名 ASC"); //升序排列，desc為降序排列。  
    example.setDistinct(false)//去除重複，boolean型，true為選擇不重複的記錄。  
    Criteria criteria = new Example().createCriteria();  
    is null;is not null;  
    equal to(value);not equal to(value);  
    GreaterThan(value);GreaterThanOrEqualTo(value);  
    LessThan(value); LessThanOrEqualTo(value);  
    in(item,item,item,...);not in(item,item,item,...);  
    like("%"+value+"%");not like("%"+value+"%");  
    Between(value1,value2);not between(value1,value2)  
      
       
      
    mybatis中mapper的例項函式:  
    int countByExample(UserExample example) thorws SQLException：按條件計數。  
    int deleteByPrimaryKey(Integer id) thorws SQLException：按主鍵刪除。  
    int deleteByExample(UserExample example) thorws SQLException：按條件刪除。  
    String/Integer insert(User record) thorws SQLException：插入(返回值為id值)  
    User selectByPrimaryKey(Integer id) thorws SQLException：按主鍵查詢。  
    List<?>selectByExample(UserExample example) thorws SQLException：按條件查詢  
    List<?>selectByExampleWithBLOGs(UserExample example) thorws SQLException：按  
      
    條件查詢（包括BLOB欄位）。只有當資料表中的欄位型別有為二進位制的才會產生。  
    int updateByPrimaryKey(User record) thorws SQLException：按主鍵更新  
    int updateByPrimaryKeySelective(User record) thorws SQLException：按主鍵更新  
      
     值不為null的欄位  
    int updateByExample(User record, UserExample example) thorws SQLException：   
      
    按條件更新  
    int updateByExampleSelective(User record, UserExample example) thorws    
      
    SQLException：按條件更新值不為null的欄位  
      
    mybatis中mapper的例項函式詳解：  
    ① selectByPrimaryKey()  
      
    User user = ##Mapper.selectByPrimaryKey(100); 相當於select * from user where  
      
    id = 100  
      
    ② selectByExample() 和 selectByExampleWithBLOGs()  
      
    UserExample example = new UserExample();  
    Criteria criteria = example.createCriteria();  
    criteria.andUsernameEqualTo("joe");  
    criteria.andUsernameIsNull();  
    example.setOrderByClause("username asc,email desc");  
    List<?>list = ##Mapper.selectByExample(example);  
    相當於：select * from user where username = 'joe' and username is null order  
      
    by username asc,email desc  
      
    注：在iBator 生成的檔案UserExample.java中包含一個static 的內部類 Criteria ，  
      
    在Criteria中有很多方法，主要是定義SQL 語句where後的查詢條件。  
      
    ③ insert()  
      
    User user = new User();  
    user.setId(101);  
    user.setUsername("test");  
    user.setPassword("123")  
    user.setEmail("
 
[email protected]");  
    ##Mapper.insert(user);  
    相當於：insert into user(ID,username,password,email) values  
      
    (101,'test','123','[email protected]');  
      
     ④ updateByPrimaryKey() 和 updateByPrimaryKeySelective()  
      
    User user =new User();  
    user.setId(101);  
    user.setUsername("joe");  
    user.setPassword("joe");  
    user.setEmail("
 
[email protected]");  
    ##Mapper.updateByPrimaryKey(user);  
    相當於：update user set username='joe',password='joe',email='[email protected]'  
      
    where id=101  
      
    User user = new User();  
    user.setId(101);  
    user.setPassword("joe");  
    ##Mapper.updateByPrimaryKeySelective(user);  
    相當於：update user set password='joe' where id=101  
      
    ⑤ updateByExample() 和 updateByExampleSelective()  
      
    UserExample example = new UserExample();  
    Criteria criteria = example.createCriteria();  
    criteria.andUsernameEqualTo("joe");  
    User user = new User();  
    user.setPassword("123");  
    ##Mapper.updateByPrimaryKeySelective(user,example);  
    相當於：update user set password='123' where username='joe'  
      
    ⑥ deleteByPrimaryKey()  
      
    ##Mapper.deleteByPrimaryKey(101);  相當於：delete from user where id=101  
      
    ⑦ deleteByExample()  
      
    UserExample example = new UserExample();  
    Criteria criteria = example.createCriteria();  
    criteria.andUsernameEqualTo("joe");  
    ##Mapper.deleteByExample(example);  
    相當於：delete from user where username='joe'  
      
    ⑧ countByExample()  
      
    UserExample example = new UserExample();  
    Criteria criteria = example.createCriteria();  
    criteria.andUsernameEqualTo("joe");  
    int count = ##Mapper.countByExample(example);  
    相當於：select count(*) from user where username='joe'