MySQL find_in_set function not work as expect Now I am using this command to query user_id not in collections, this is my sql:
select *
from report_user_foundation
where !FIND_IN_SET(user_id ,(
    select GROUP_CONCAT(login_user_ids) as bet_user_ids
    from report_summary rs 
    where statistic_time &gt;= 1606752000000)
)

I query user id from table report_user_foundation that not in report_summary table login_user_ids column. but when the using the result user id to query in report_summary that still exists.
select login_user_ids 
from report_summary rs 
where login_user_ids like '%4685%'

Am I sql is not correct? Am I missing something?
FIND_IN_SET ( GROUP_CONCAT ) -- cleaver, but clunky.  Instead of
select *
from report_user_foundation
where !FIND_IN_SET(user_id ,(
    select GROUP_CONCAT(login_user_ids) as bet_user_ids
    from report_summary rs 
    where statistic_time &gt;= 1606752000000)
)

do
SELECT *
    FROM report_user_foundation AS rsf
    WHERE NOT EXISTS(
            SELECT 1 FROM report_summary
                   ON rsf.user_id = login_user_ids
                  AND statistic_time &gt;= 1606752000000
                    )
   /* AND login_user_ids like '%4685%' */

or, alternatively,
SELECT rsf.*
    FROM report_user_foundation AS rsf
    LEFT JOIN report_summary rs
                   ON rsf.user_id = rs.login_user_ids
                  AND rs.statistic_time &gt;= 1606752000000
    WHERE rs.id IS NULL
   /* AND login_user_ids like '%4685%' */

Alas, I don't understand your comment about where login_user_ids like '%4685%'.  Perhaps it goes where I put the comments.
If these tables get big, this composite index may help:
report_summary:  INDEX(login_user_ids, statistic_time)