1下翎、Hibernate是全ORM(對(duì)象關(guān)系映射)框架,利用完整的javabean對(duì)象與數(shù)據(jù)庫(kù)映射結(jié)構(gòu)來(lái)自動(dòng)生成sql采驻。
2审胚、Mybatis是半ORM框,僅有字段映射礼旅,需要手寫sql語(yǔ)句和對(duì)象字段結(jié)合生成最終的執(zhí)行sql語(yǔ)句膳叨。
3、Mybatis-plus是Mybatis的增強(qiáng)版痘系,支持所有Mybatis的原生特性菲嘴。核心的特性的是ActiveRecord,實(shí)體類只需繼承 Model 類即可實(shí)現(xiàn)基本 CRUD 操作汰翠。
mybtis-plus適合快速地單表CRUD,將業(yè)務(wù)邏輯寫在代碼服務(wù)層龄坪,不必再拼接復(fù)雜的sql。
復(fù)雜sql在數(shù)據(jù)庫(kù)層面執(zhí)行效率低复唤,且數(shù)據(jù)庫(kù)不適于擴(kuò)容增加性能健田;
代碼層面結(jié)合java8的流式編程,可以快速進(jìn)行數(shù)據(jù)的聚合佛纫、過濾處理妓局。
官方講的比較詳細(xì):https://baomidou.com/pages/24112f/
/**
* <p>
* 根據(jù)根據(jù) entity 條件,刪除記錄,QueryWrapper實(shí)體對(duì)象封裝操作類(可以為 null)
* 下方獲取到queryWrapper后刪除的查詢條件為name字段為null的and年齡大于等于12的and email字段不為null的
* 同理寫法條件添加的方式就不做過多介紹了雳旅。
* </p>
/
@Test
public void delete() {
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
queryWrapper
.isNull("name")
.ge("age", 12)
.isNotNull("email");
int delete = mapper.delete(queryWrapper);
System.out.println("delete return count = " + delete);
}
/*
* <p>
* 根據(jù) entity 條件跟磨,查詢一條記錄,
* 這里和上方刪除構(gòu)造條件一樣间聊,只是seletOne返回的是一條實(shí)體記錄攒盈,當(dāng)出現(xiàn)多條時(shí)會(huì)報(bào)錯(cuò)
* </p>
/
@Test
public void selectOne() {
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("name", "lqf");
User user = mapper.selectOne(queryWrapper);
System.out.println(user);
}
/*
* <p>
* 根據(jù) Wrapper 條件,查詢總記錄數(shù)
* </p>
*
* @param queryWrapper 實(shí)體對(duì)象
/
@Test
public void selectCount() {
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
queryWrapper.eq("name", "lqf");
Integer count = mapper.selectCount(queryWrapper);
System.out.println(count);
}
/*
* <p>
* 根據(jù) entity 條件哎榴,查詢?nèi)坑涗?br>
* </p>
*
* @param queryWrapper 實(shí)體對(duì)象封裝操作類(可以為 null)為null查詢?nèi)?br>
/
@Test
public void selectList() {
List<User> list = mapper.selectList(null);
System.out.println(list);
}
/*
* <p>
* 根據(jù) Wrapper 條件型豁,查詢?nèi)坑涗?br>
* </p>
*
* @param queryWrapper 實(shí)體對(duì)象封裝操作類(可以為 null)
/
@Test
public void selectMaps() {
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
queryWrapper.isNotNull("name");
List<Map<String, Object>> maps = mapper.selectMaps(queryWrapper);
for (Map<String, Object> map : maps) {
System.out.println(map);
}
}
/*
* 打印結(jié)果
* {name=lqf, id=1046282328366391406, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391407, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391408, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391409, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391410, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391411, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391412, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391413, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391414, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391415, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391416, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391417, age=12, email=lqf@163.com, status=false}
* {name=lqf, id=1046282328366391418, age=12, email=lqf@163.com, status=false}
* json類型的鍵值對(duì)模式
/
/*
* <p>
* 根據(jù) entity 條件,查詢?nèi)坑涗洠ú⒎?yè))
* </p>
*
* @param page 分頁(yè)查詢條件(可以為 RowBounds.DEFAULT)
* @param queryWrapper 實(shí)體對(duì)象封裝操作類(可以為 null)
/
@Test
public void selectPage() {
Page<User> page = new Page<>(1, 5);
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
IPage<User> userIPage = mapper.selectPage(page, queryWrapper);
System.out.println(userIPage);
}
/*
* 打印結(jié)果
* ==> Preparing: SELECT COUNT(1) FROM user
* ==> Parameters:
* <== Columns: COUNT(1)
* <== Row: 100
* ==> Preparing: SELECT id,name,age,email,status FROM user LIMIT 0,5
* ==> Parameters:
* <== Columns: id, name, age, email, status
* <== Row: 1046282328366391319, lqf, 12, lqf@163.com, 0
* <== Row: 1046282328366391320, lqf, 12, lqf@163.com, 0
* <== Row: 1046282328366391321, lqf, 12, lqf@163.com, 0
* <== Row: 1046282328366391322, lqf, 12, lqf@163.com, 0
* <== Row: 1046282328366391323, lqf, 12, lqf@163.com, 0
* <== Total: 5
*
*
* 這里需要在項(xiàng)目中加入分頁(yè)插件
* @Bean
* public PaginationInterceptor paginationInterceptor() {
* return new PaginationInterceptor();
* }
/
/*
* <p>
* 根據(jù) Wrapper 條件尚蝌,查詢?nèi)坑涗洠ú⒎?yè))
* </p>
*
* @param page 分頁(yè)查詢條件
* @param queryWrapper 實(shí)體對(duì)象封裝操作類
/
@Test
public void selectMapsPage() {
Page<User> page = new Page<>(1, 5);
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
IPage<Map<String, Object>> mapIPage = mapper.selectMapsPage(page, queryWrapper);
System.out.println(mapIPage);
}
/*
* 和上個(gè)分頁(yè)同理只是返回類型不同
/
/*
* <p>
* 根據(jù) whereEntity 條件迎变,更新記錄
* </p>
*
* @param entity 實(shí)體對(duì)象 (set 條件值,不能為 null)
* @param updateWrapper 實(shí)體對(duì)象封裝操作類(可以為 null,里面的 entity 用于生成 where 語(yǔ)句)
/
@Test
public void update() {
//修改值
User user = new User();
user.setStatus(true);
user.setName("zhangsan");
//修改條件s
UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
userUpdateWrapper.eq("name", "lqf");
int update = mapper.update(user, userUpdateWrapper);
System.out.println(update);
}
/*
* 打印結(jié)果
* ==> Preparing: UPDATE user SET name=?, status=? WHERE name = ?
* ==> Parameters: zhangsan(String), true(Boolean), lqf(String)
* <== Updates: 100
* Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@56a4f272]
* 100
* 2018-10-02 15:08:03.928 INFO 7972 --- [ Thread-2] o.s.w.c.s.GenericWebApplicationContext : Closing org.springframework.web.context.support.GenericWebApplicationContext@37313c65: startup date [Tue Oct 02 15:08:00 CST 2018]; root of context hierarchy
* 2018-10-02 15:08:03.937 INFO 7972 --- [ Thread-2] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated...
* 2018-10-02 15:08:04.053 INFO 7972 --- [ Thread-2] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed.
*
* Process finished with exit code 0
*/
}