@Select({"<script>", "SELECT IFNULL(sum( IFNULL(detail.amount,0) ),0) as total FROM T_Lhgy_Work_Plan plan, T_Lhgy_Work_Plan_Detail detail WHERE plan.id = detail.plan_id AND plan.delete_flag = 0 AND detail.delete
contractMgt.getPackageId());contract_wrapper.select("ifnull(sum(amount_total),0) as total ");Map<String,Object>map=contractMgtService.getMap(contract_wrapper);Doublepackage_total_amount=Double.valueOf(String.valueOf(map.get("total")));...
如果你使用的是XML方式编写SQL语句,可以在<if>标签中进行空值或null的判断。 XML 示例: xml <select id="selectByCondition" resultType="com.example.entity.YourEntity"> SELECT * FROM your_table <where> <if test="yourParam != null and yourParam != ''"> AND your...
Set<Integer> subIds = stuSubRelations.stream().map(StuSubRelation::getSubId).collect(toSet()); if (stuIds.size() > 0 && subIds.size() > 0) { HashBasedTable<Integer, Integer, Integer> table = getHashBasedTable(stuSubRelations); List<Subject> subList = subjectMapper.selectList(Wrapper...
queryWrapper.select("IFNULL( max(percent),0) as maxPercent"); Map<String, Integer> map =getMap(queryWrapper);returnmap.get("maxPercent"); postgresql数据库查询写法 QueryWrapper queryWrapper=new QueryWrapper<>(); queryWrapper.select("COALESCE(max(priority) ,0)asmaxpriority"); ...
selectList(userQueryWrapper); System.out.println("userList:"+userList); //MyBatis-Plus 在 QueryWrapper 中使用 SUM 聚合函数 // 统计查询(sum):count 为需要sum的字段 QueryWrapper<InOutCount> inOutCountQueryWrapper = new QueryWrapper<>(); inOutCountQueryWrapper.select("IFNULL(SUM(count), 0) ...
QueryWrapper<Org> queryWrapper= new QueryWrapper<Org>(); queryWrapper.eq("org_id", orgId); queryWrapper.select("IFNULL(sum(balance),0) as total "); Map<String, Object> map = getMap(queryWrapper); BigDecimal total = new BigDecimal(String.valueOf(map.get("total"))); And,Or一起用 Quer...
3.select 数据丢失 如果某列存在 NULL 值时,如果执行非等于查询(<>或者!=)会导致为 NULL 值的结果丢失,比如下面的这些数据: 当我们查询name不等于"Java"的所有数据时,预期结果应该是id从2到10的数据,但是执行以下sql查询时 查询结果如下所示: 可以看出id=9和id=10的name为 NULL 的两条数据没有查询出来,这...
select sex, ifnull(count(id), 0) AS num, CASE WHEN sex = 1 THEN '男' WHEN sex = 0 THEN '女' ELSE '未知' END AS sexStr from xxx group by sex where status = 0 LambdaQueryWrapper<xxxDO>queryWrapper=newQueryWrapper<xxxDO>().select("sex, ifnull(count(id), 0) AS num, CASE WHE...
select(subBoList, e -> emptyIfNull(map.get(studentVo.getId())).contains(e.getId())); list.forEach(e -> e.setScore(table.get(studentVo.getId(), e.getId())); studentVo.setSubList(list); } } return studentVoPage; } 2、理论分析 多对多N条记录分页查询由于使用了批查询,因此最多访问...