Laravel HasManyThrough with 3-way pivot table - php

Question

I have the following models
Recipe
public function ingredientRecipeUnits()
{
return $this->hasMany(IngredientRecipeUnit::class);
}
Ingredient
public function ingredientRecipeUnits()
{
return $this->hasMany(IngredientRecipeUnit::class);
}
Unit
public function ingredientRecipeUnits()
{
return $this->hasMany(IngredientRecipeUnit::class);
}
and a pivot table (in its own model) connecting all three:
IngredientRecipeUnit
public function ingredient()
{
return $this->belongsTo(Ingredient::class);
}
public function recipe()
{
return $this->belongsTo(Recipe::class);
}
public function unit()
{
return $this->belongsTo(Unit::class);
}
I would like to fetch all Recipes through the ingredient model.
For this I made the following relationship:
public function recipes() {
return $this->hasManyThrough(
Recipe::class,
IngredientRecipeUnit::class,
'ingredient_id',
'id'
);
}
This generates an incorrect query looking like this
select * from `recipes`
inner join `ingredient_recipe_units`
on `ingredient_recipe_units`.`id` = `recipes`.`id`
where `ingredient_recipe_units`.`ingredient_id` = ?
while in reality the query should look like this. (Notice subtle change of id -> recipe_id on line 3)
select * from 'recipes'
inner join `ingredient_recipe_units`
on `ingredient_recipe_units`.`recipe_id` = `recipes`.`id`
where `ingredient_recipe_units`.`ingredient_id` = ?
Besides sending a pull-request to the Eloquent repo to add an extra Parameter or using raw SQL; is there any way to solve this?

Answer 1

This ended up being a mistake in the way I thought up the relationship and it was solved by simply defining a belongsToMany from the individual related models directly to the IngredientRecipeUnit table.
ex: Ingredient Model
public function recipes() {
return $this->belongsToMany(Recipe::class, 'ingredient_recipe_units');
}
Depending on your model you might have the possibility to add multiple of the same ingredient or unit, in this case you should mark the query with the instinct method.
Like this:
public function recipes() {
return $this->belongsToMany(Recipe::class, 'ingredient_recipe_units')->distinct();
}
Which correclty generates the following desired query:
select distinct * from `recipes`
inner join `ingredient_recipe_units`
on `recipes`.`id` = `ingredient_recipe_units`.`recipe_id`
where `ingredient_recipe_units`.`ingredient_id` = ?