Level 51
@vaughn-kennett Like parent and child?
Sep 1, 2021
9
Level 10
Many to Many Table - same table?
Wondering if this is possible - would like a single M-M table of cascading questions:
Q1 Title of Question 1
Q2 Title of Question 2
Q3 Title of Question 3
Q4 Title of Question 4
Q5 Title of Question 5
obviously the table structure could be a combination of multiple seperate tables - for each level:
Q1 Title of Question One
Q1-1 Title of Question 1-1
Q1-2 Title of Question 1-2
Q1-2-1 Title of Question 1-2-1
Q2 Title of Question 2
but I would like a single table of questions, that point to themselves? i.e. Table containing
Q1 - with Q2, and Q3
Q3 - with Q4
i.e a single table of cascading items.
The M-M relationship has the issue of the question_question pivot table containing 2 ids of the same name, question_id and question_id which causes the obvious error.
Has anybody used this approach of a M-M table, pointing to itself? Or is this obviously not possible?
Level 51
@jeffreyway, hey there. It seems there is a parsing issue with at mention for this username with a dash @vaughn-kennett
Level 10
Hi webrobert The structure is parent-child....->no limit on levels, but all items are in the same table, does that make sense?
Level 10
removed the dash from the username
Level 51
@vaughnkennett, You just need a parent_id column and you can create a relationship to self. In the model
public function parent()
{
return $this->hasOne(Question::class,'id', 'parent_id');
}
public function children()
{
return $this->hasMany(Question::class, 'parent_id', 'id');
}
But I’m on my phone right now and I may have The syntax wrong here for the model.
Level 10
THanks webrobert - will test it out, appreciate your quick response.
Level 51
the tricky part is actually being able to show them infinitely. There is a great video here on that. It’s old but the concept still works.
Level 55
@vaughnkennett I can recomment to look at Nested Set https://en.wikipedia.org/wiki/Nested_set_model
there are also package which implements it for laravel https://github.com/lazychaser/laravel-nestedset
Level 10
Thanks Silencebringer - will do some reading, and test this out too. Appreciate the links to subject matter.
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