如何從select子查詢中存儲多個值

Question

嗨，我在以下查詢中遇到問題：

Update tbl 
set somecol = somecol 
Where Key = (select key  
             from tbl
             group by key 
             having count(*) > 1)  
  and Time = (select max(time) from tbl) 

當只有一個鍵時，上面的查詢工作正常。 但是，如果有多個鍵，則此查詢不起作用。 如何從select子查詢中存儲多個值？ 時間列也可以是多個。 我是sql的新手。 請指導。 提前致謝。

Answer 1

使用IN謂詞：

Update tbl 
set somecol = somecol 
Where Key in (select key  
             from tbl
             group by key 
             having count(*) > 1)  
  and Time = (select max(time) from tbl)

Answer 2

請嘗試以下方法：

Update tbl 
set somecol = somecol 
Where Key in (select key  
             from tbl
             group by key 
             having count(*) > 1)  
  and Time in (select max(time) from tbl) 

根據要求，您還可以使用派生表。