MYSQL uses Limit to Limit the number of updated rows to modify the config table. Change is_ OK of row 5607 to true. The following SQL statement is used to implement the SQL code UPDATE channel_config set is_adam_pub = 1 where channel_id in (select channel_id from channel_config limit 5607). It is found that Mysql does not support Limit clauses, the database reports This version of MySQL doesn't yet support 'limit & IN/ALL/ANY/SOME subquery, you can use the LimitSql code UPDATE channel_config set is_adam_pub = 1 where channel_id in (select t. channel_id from (select channel_id from channel_config limit 5607) as t); in this way, although the results can be achieved, the execution is very slow and it takes 15.815 ms to think about it, does update have limit usage? SQL code UPDATE channel_config set is_adam_pub = 1 LIMIT 5607; found that it was successful, and 0.102 ms -- end --