MongoDB - how to join parent and child products by reference
- by Jaro
my mongo collection stores products. There are two product types: child and parent. Parent product holds array of its child as reference.
Use case:
use mydb;
child1 = {
_id: 1,
name: "Child 1",
is_child: true,
is_parent: false,
children : []
}
child2 = {
_id: 2,
name: "Child 2",
is_child: true,
is_parent: false,
children : []
}
parent = {
_id: 3,
name: "Parent product",
is_child: false,
is_parent: true,
children : [1, 2]
}
db.product.insert( [child1, child2, parent] );
And I'm looking for any query returning
{
_id: 3,
name: "Parent product",
is_child: false,
is_parent: true,
children: [
{
_id: 1,
name: "Child 1",
is_child: true,
is_parent: false,
children : []
},
{
_id: 2,
name: "Child 2",
is_child: true,
is_parent: false,
children : []
}
]
}
I'm newbie to mongodb, but I guess an usage of map-reduce could solve the problem. Can anyone advice? Thx
