sql - Is there a way to speed up this MySQL delete query? -

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i’m using mysql 5.5.37. i’m trying figure out faster way write below query. have 2 tables, access_code , classroom. “classroom” table has foreign key constraint (access_code_id) primary key of access_code table. i’m trying delete records in access_code table have no link classroom table , have particular type id. i’m running …

delete access_code id in (select q.* (select a.id access_code left join lyc_classroom c on a.id = c.access_code_id a.access_code_type = 2 , c.access_code_id null) q);

which taking long time. there faster way execute above query?

you don't need subqueries. use delete ... join syntax

delete  access_code left join lyc_classroom c on a.id = c.access_code_id a.access_code_type = 2 , c.access_code_id null

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