CloudKit - 如何执行Not Exists查询？

Question

我想在CloudKit中执行数据库查询，就像在SQL中一样：

SELECT *
FROM table1 t1
WHERE NOT EXISTS 
    (SELECT *
    FROM table2 t2
    WHERE t1.userid = t2.userid)

你知道怎么做吗？

Answer 1

尝试 选择 * FROM table1 t1 在哪里t1.userid NOT IN（     SELECT t2.userid     FROM table2 t2）;

或

SELECT t1.userid FROM table1 t1 减去 SELECT t2.userid FROM table2 t2;