{ // 第一步:查询出name重复的记录 LambdaQueryWrapper<User> duplicateNameWrapper = new LambdaQueryWrapper<>(); duplicateNameWrapper.groupBy(User::getName) .having("COUNT(name) > 1"); List<User> duplicateNameUsers = userMapper.selectList(duplicateNameWrapper); // 第二...
orderByDesc(R... columns); // 等价于 ORDER BY 字段, ... DESC, 例: orderByDesc("id", "name") ---> order by id DESC,name DESC having(String sqlHaving, Object... params); // 等价于 HAVING ( sql语句 ), 例: having("sum(age) > {0}", 11) ---> having sum(age) > 11 ...
5、【分组、排序:(group、having、order)】 groupBy(R... columns); // 等价于 GROUP BY 字段, ..., 例: groupBy("id", "name") ---> group by id,name orderByAsc(R... columns); // 等价于 ORDER BY 字段, ... ASC, 例: orderByAsc("id", "name") ---> order by id ASC,name ...
// 使用Wrappers工具类 LambdaQueryWrapper<User> lambdaQueryWrapper = Wrappers.<User>lambdaQuery(); // new关键字 QueryWrapper<User> queryWrapper = new QueryWrapper<>(); queryWrapper.like(StringUtils.isNotBlank(name), "name", name) // 链式语法:LambdaQueryChainWrapper List<User> userList = new Lamb...
wrapper.orderByDesc("age", "name"); // 16.分组查询,用于按照指定字段进行分组查询。 QueryWrapper<User> wrapper = new QueryWrapper<>(); wrapper.select("age", "count(*)").groupBy("age"); // 17.HAVING 子句查询,用于筛选分组查询结果。
String dsSourceName = queryForm.getDsSourceName(); String dsNewsColumns = queryForm.getDsNewsColumns(); if (!StringUtil.isEmpty(dsCode)) { lqw.likeRight(Ds::getDsCode, SqlUtil.escapeLike(dsCode)); lqw.groupBy(Ds::getDsCode).having("count (0) >1"); ...
函数接口 Func<Children, R>,如 in 查询、groupby 分组、having、order by排序等 常用的 where 条件表达式 eq、like、in、ne、gt、ge、lt、le。 SQL 片段函数接口 lambda 这么好用的秘诀在于SQL 片段函数接口:ISqlSegment,我们在 doIt 方法找到 ISqlSegment 对象参数,翻开 ISqlSegment 源码,发现它真实的庐山真...
wrapper.lambda().eq(BannerItem::getBannerId, id); List<BannerItem> bannerItems = bannerItemMapper.selectList(wrapper); LambdaQueryWrapper 为了简化lambda的使用,我们可以改写成LambdaQueryWrapper构造器,语法如下: LambdaQueryWrapper<BannerItem> wrapper =newQueryWrapper<BannerItem>().lambda(); ...
@Test public void testLambdaQueryOfOr_And() { LambdaQueryWrapper<UserEntity> lqw = Wrappers.lambdaQuery(); lqw.eq(UserEntity::getSex, 0L) .and(wrapper->wrapper.eq(UserEntity::getUserName,"dunzung") .or().ge(UserEntity::getAge, 50)); List<UserEntity> userList = userMapper.selectList...
System.out.println("---链式查询不支持分组过滤。直接使用基础的QueryWrapper--分组过滤 groupBy having"); QueryWrapperwrapper=new QueryWrapper<>(); wrapper.select("version","sum(age) as num") .groupBy("version") .having("sum(age)>0")