找出两个不同查询SQL总数之间的差异

Question

我有一个表Vocab，我想找到总行数和重复数，这是我试过的代码

(SELECT COUNT(*) FROM Vocab) - (SELECT COUNT(*) FROM Vocab GROUP BY Word) 但它给我一个错误Unexpected token. (near "-" at position 29)，我怎样才能实现我的目标？

Answer 1

我认为你想要count(distinct)和一些算术：

select count(*) as total_words,
       count(distinct word) as total_distinct_words,
       (count(*) - count(distinct word)) as must_be_duplicated
from Vocab;