標籤：刪除 去除 art select distinct 排列 app exception primary
- ##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)
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- mybatis中mapper的執行個體函數:
- 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(傳回值為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
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- 條件查詢（包括BLOB欄位）。只有當資料表中的欄位類型有為二進位的才會產生。
- int updateByPrimaryKey(User record) thorws SQLException：按主鍵更新
- int updateByPrimaryKeySelective(User record) thorws SQLException：按主鍵更新
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- 值不為null的欄位
- int updateByExample(User record, UserExample example) thorws SQLException：
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- 按條件更新
- int updateByExampleSelective(User record, UserExample example) thorws
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- SQLException：按條件更新值不為null的欄位
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- mybatis中mapper的執行個體函數詳解：
- ① selectByPrimaryKey()
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- User user = ##Mapper.selectByPrimaryKey(100); 相當於select * from user where
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- id = 100
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- ② selectByExample() 和 selectByExampleWithBLOGs()
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- 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
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- by username asc,email desc
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- 註：在iBator 產生的檔案UserExample.java中包含一個static 的內部類 Criteria ，
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- 在Criteria中有很多方法，主要是定義SQL 語句where後的查詢條件。
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- ③ insert()
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- 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
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- (101,‘test‘,‘123‘,‘[email protected]‘);
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- ④ updateByPrimaryKey() 和 updateByPrimaryKeySelective()
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- 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]‘
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- where id=101
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- User user = new User();
- user.setId(101);
- user.setPassword("joe");
- ##Mapper.updateByPrimaryKeySelective(user);
- 相當於：update user set password=‘joe‘ where id=101
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- ⑤ updateByExample() 和 updateByExampleSelective()
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- 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‘
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- ⑥ deleteByPrimaryKey()
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- ##Mapper.deleteByPrimaryKey(101); 相當於：delete from user where id=101
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- ⑦ deleteByExample()
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- UserExample example = new UserExample();
- Criteria criteria = example.createCriteria();
- criteria.andUsernameEqualTo("joe");
- ##Mapper.deleteByExample(example);
- 相當於：delete from user where username=‘joe‘
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- ⑧ countByExample()
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- 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‘
mybatis中的mapper介面檔案以及example類的執行個體函數以及詳解
