What about relationships from the child up to the parent? Are they also classified as N+1?

Suppose we have child table with a fk of parent_id.

if I do:

 SELECT * from CHILD

I'll get a column with parent_id with values.

Now suppose I also want details pertaining to the parent_id along with the recordset of Child, I need not
do 10 separate selects for the parent ... is this also an N+1 problem?


What is the preferred iBatis model for this?

Cheers

Abdullah


Kris Jenkins wrote:

friendVU admin wrote:

What is n+1?
.V



n++! :-P

It's when each child object in a complex query has to be selected seperately. If 'parent' has 10 'children', you end up with 10+1 select statements being issued. See the developer's guide under 'Avoiding N+1 selects' for the full lowdown. Version 2.0.9 comes with new groupBy goodness to banish the N+1 problem.

Kris

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