子查询中的varchar数据类型的聚合子句

Question

我想用子查询执行以下操作，即使我可以用另一种方式执行。我正在查询一个大型联结表，在该查询内部，我希望计算出超过X次的所有县名。

select v.id, k.countyName
from v inner join k on v.countyID=k.countyID inner join
icd_jxn on v.id = icd_jxn.id
where k.countyName in
(select count(k.countyName) from k
having count(k.countyName) > 10)

给出的错误是conversion failed when converting the varchar value X to int。我不想做任何转换，我只是想要多次将县名出现在桌面上。

Answer 1

您的内部查询仅返回计数。您的查询需要是：

select v.id, k.countyName 
from v inner join k on v.countyID=k.countyID inner join 
icd_jxn on v.id = icd_jxn.id 
where k.countyName in 
(select k.countyName from k 
group by k.countyName
having count(k.countyName) > 10) 

Answer 2

您可以尝试以下

select v.id, k.countyName
from v inner join k on v.countyID=k.countyID 
       inner join icd_jxn on v.id = icd_jxn.id
where k.countyName in
(
    select k.countyName from k
    group by k.countyName
    having count(k.countyName) > 10
)

问题是您选择了count并检查了IN子查询中的varchar类型。因此，您应该选择countyName

Answer 3

您正在尝试查看国家/地区名称IN的计数（从而将varchar与整数进行比较）

select v.id, k.countyName
from v 
inner join k on v.countyID=k.countyID 
inner join icd_jxn on v.id = icd_jxn.id
where k.countyName in
(
   select k.countyName as c from k
   having count(k.countyName) > 10 
   group by k.countyName
)

Answer 4

在您的查询中，您正在将k.CountryName varchar类型转换为导致错误的Count int类型。 试试这个

select v.id, k.countyName
from v inner join k on v.countyID=k.countyID inner join
icd_jxn on v.id = icd_jxn.id
where k.countyName in
(select k.countyName from k
group by k.countyName
having count(k.countyName) > 10)