我不会问有关SQLite的数据库浏览器中的表关系,我有一个具有UserID字段的表名(User),然后有一个具有LetterID字段的表名(Letter),最后,我有一个表(成绩)在此表中,我希望所有的userID都具有所有的LetterID,但我无法通过任何方式获取此信息,请帮助我
Sounds like you're after a Cartesian product. A cross join produces that.
SELECT u.userid,
l.letterid
FROM user u
CROSS JOIN letter l;
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