sql - MySQL how to find parent with exact set of children? -

mysql 5.5

 parent table: id | facts 

 child table: parent_id | foreign_key | facts 

now, want find parents have exact set of children, no more, no less. like:

select t1.`id`  `parent_table` t1    left join `child_table` t2 on t1.id=t2.parent_id t2.`fk` = 1    , t2.`fk` = 3     , t2.`fk` = 5    , t2.`fk` = 7    , t2.`fk` = 9 

but parent record set of children: 1,2,3,5,7,9. , want parents have the exact set of children: 1,3,5,7,9.

is there way?

edit: child.parent_id , child.fk both not unique. child.fk foreign key linking table. ("many-to-many relationship") quite possible parent have children 1,2,3,5,7,9. whole reason doing query try avoid creating new parent 1,3,5,7,9 if such parent exists.

assuming child.id unique every child.parent_id.

select  a.id, a.facts    parent         inner join child b             on a.id = b.parent_id   b.id in (1,3,5,7,9) ,        -- <<== list childid here         exists                         -- <<== part checks if parent_id         (                              --           present on exists clause             select  parent_id          --           filters parents                child c            --           5 children               b.parent_id = c.parent_id             group   parent_id             having  count(*) = 5       -- <<== total number of children         ) group   a.id, a.facts having  count(*) = 5                   -- <<== total number of children 

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