选择bool，表示行的ID是否在另一个表中

Question

有没有办法使用IN语句在结果集中获取bool列？

我知道我可以做这样的事情，只选择在另一个表中找到ID的所有行，然后选择反之以选择那些没有的行，从那里得到真/假：

SELECT * FROM people WHERE id IN (SELECT staff.personID FROM staff)

但我希望能有类似的东西：

SELECT
    people.*,
    (people.id IN (SELECT staff.personID FROM staff)) AS marked
FROM people

结果：

+----+--------+--------+
| id | name   | marked |
+----+--------+--------+
| 1  | Marty  | 1      |
| 2  | Steven | 1      |
| 3  | Daniel | 0      | <--- Not found in 'staff'.
| 4  | James  | 1      |
+----+--------+--------+

Answer 1

您的查询应该有效：

SELECT people.*,
       (people.id IN (SELECT staff.personID FROM staff)) AS marked
FROM people;

我认为它会更有效率：

SELECT p.*,
       (exists (SELECT 1 FROM staff s WHERE s.PersonID = p.id)) AS marked
FROM people p;