迭代通過兩列，並比較他們

Question

我有兩列這樣的：

結果集1：select sPersonID from tPersonData where x < 50

結果集2：select sPersonID from tPersonData where x > 50

我想通過柱1迭代和要檢查，如果每sPeronID存在於列至少1次，2列

樣本數據：

Result-Set 1: 
00/510 
00/650 
00/644 
00/690 

Result-Set 2: 
00/510 
00/640 
00/644 

和預期的結果應該是像TRUE/FALSE

Answer 1

自我從左側加入使用左tPersonData加入和組由sPersonID和計算的相應的記錄，從右邊數：

select t1.sPersonID, if(count(t2.sPersonID)=0,'false','true') as result 
from tPersonData t1 
left join tPersonData t2 on t1.sPersonID=t2.sPersonID and t2.x>50 
where t1.x<50 
group by t1.sPersonID 

Answer 2

你可以試試這個

select case 
     when a = b then 
      'TRUE' 
     else 
      'FALSE' 
     end 
    from (select (select COUNT(sPersonID) 
        from tPersonData t1 
       where t1.x < 50 
        AND t1.sPersonID IN 
         (select sPersonID from tPersonData where x > 50)) a, 
       (select COUNT(sPersonID) from tPersonData t1 where t1.x < 50) b 
      from dual)