MyBatis Plus 在復雜查詢條件Where中加括號,多個查詢條件在括號內


一、MyBatis Plus 在復雜查詢條件Where中加括號,多個查詢條件在括號內

使用and()方法

官方給出示例:

and(i -> i.eq("name", "李白").ne("status", "活着"))

---> sql輸出結果:and (name = '李白' and status <> '活着')

二、QueryWrapper無條件時

1  QueryWrapper<Demo> queryWrapper = new QueryWrapper<>();
2         queryWrapper.and(query -> query.like(StringUtils.isNotBlank(demo.getName()), "demo.name", demo.getName()).or().
3  like(StringUtils.isNotBlank(demo.getFrontId()), "demo.frontId", demo.getFrontId()));
4  
5  ------> sql輸出結果:
6  select id, name, frontId from demo where ( turbine.name LIKE '%測%'  OR turbine.frontId LIKE '%測%') 

三、QueryWrapper有條件時

 

1  QueryWrapper<Demo> queryWrapper = new QueryWrapper<>();
2  queryWrapper.eq("id",demo.getId);
3 queryWrapper.and(query -> query.like(StringUtils.isNotBlank(demo.getName()), "demo.name", demo.getName()).or().
4 like(StringUtils.isNotBlank(demo.getFrontId()), "demo.frontId", demo.getFrontId()));
5  
6  ------> sql輸出結果:
7  select id, name, frontId from demo where id = 1 and ( turbine.name LIKE '%測%'  OR turbine.frontId LIKE '%測%') 

四、理解MyBatis Plusand()方法

  • 如果QueryWrapper對象沒有查詢條件,則只會在where語句中添加 ()
  • 如果QueryWrapper對象中有查詢條件了,會在where語句中自動添加 and(查詢條件)

五:基於queryWrapper實現分頁查詢

LambdaQueryWrapper<> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.like(StringUtils.isNoneBlank(rectificationActivityInfo.getActivityName()),RectificationActivityInfo::getActivityName,rectificationActivityInfo.getActivityName());
        queryWrapper.eq(StringUtils.isNoneBlank(rectificationActivityInfo.getStatus()),RectificationActivityInfo::getStatus,rectificationActivityInfo.getStatus());
        IPage<RectificationActivityInfo> page1 = this.page(page, queryWrapper);

 六:lambdaQueryWrapper 基於復雜sql的使用;

1  LambdaQueryWrapper<CarInfo> wrapper = new LambdaQueryWrapper<>();
2         wrapper.eq(CarInfo::getUsername,username);
3         wrapper.and(StringUtils.isBlank(VIN),x->x.eq(CarInfo::getVinNum,VIN).or(StringUtils.isBlank(autoSN),query->query.eq(CarInfo::getMachineNum,VIN)));
4         

 七、手寫sql

八、mybaties的select and  or查詢

 queryWrapper.eq("id", Id);
 queryWrapper.and(wrapper ->
                wrapper.eq("expire_time", 0)
                        .or()
                        .gt("expire_time",System.currentTimeMillis() / 1000)
);
 queryWrapper.select("sum(point) as point, sum(valid_points) as valid_points");

StudentDo studentDo = studentMapper.selectOne(queryWrapper);
===================================輸出sql
SELECT sum(point) as point, sum(valid_points) as valid_points from student where id = "111" and (expire_time = 0 or expire_time > "2555")

 九.lambdaQueryWrapper基於select字段的查詢

LambdaQueryWrapper<MdmCountry> wrapper1 = new LambdaQueryWrapper<>();
                                wrapper1.eq(MdmCountry::getCountryCode,countrycode);
                                wrapper1.select(MdmCountry::getCountryCode,MdmCountry::getCountryName,MdmCountry::getAreaId,MdmCountry::getAreaName,MdmCountry::getNationalCompanyId,MdmCountry::getNationalCompanyName);
                                List<MdmCountry> mdmCountries = mdmCountryMapper.selectList(wrapper1);

 


免責聲明!

本站轉載的文章為個人學習借鑒使用,本站對版權不負任何法律責任。如果侵犯了您的隱私權益,請聯系本站郵箱yoyou2525@163.com刪除。



 
粵ICP備18138465號   © 2018-2025 CODEPRJ.COM