How to prevent 3 nested MySQL queries from timing out -
i want delete records in t3 field names in t2 missing, if meet record id t1.
the query t1:
select max(id) t1 name1 = "xxx" , user_id = '$id'
works fine.
the t2 query:
select name2 t2 record in (select max(id) t1 name1 = "xxx" , user_id = '$id')
also works fine, takes while.
but t3 query:
delete t3 name3 not in (select name2 t2 record in (select max(id) t1 name1 = "xxx" , user_id = '$id'));
results in "#2006 - mysql server has gone away"
how query result within reasonable time?
i think can use join queries instead?
select name2, max(t1.id) t2 inner join t1 on t2.t1_id = t1.id name1="xxx" , user_id='$id'
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