Querying depth

[whoami15]

Hey there, I'm here again to ask for help.

I want to get all the parents for the given depth because I'll use it to scan if the parents in that depth have children but using where('depth', 2) didn't work because I think it only queries the first parent.

I'm expecting this to get the parents where depth is what's passed in the query.

I use treeOf and toTree instead of descendants because this gives the children of every parent.

$constraint = function ($query) use ($parentId) {
    $query->where('id', $parentId);
};

$tree = Account::query()
    ->treeOf($constraint)
    ->get()
    ->toTree();

$treeOfDepth = $tree->where('depth', 2); // this can be any depth

Given this example data returned by $tree:

[
  {
    "id": 3,
    "name": "metz",
    "parent_id": 1,
    "position": "right",
    "depth": 0,
    "path": "3",
    "children": [
      {
        "id": 24,
        "name": "ihintz",
        "parent_id": 3,
        "position": "left",
        "depth": 1,
        "path": "3.24",
        "children": [
          {
            "id": 25,
            "name": "brooks",
            "parent_id": 24,
            "position": "left",
            "depth": 2,
            "path": "3.24.25",
            "children": [
              {
                "id": 34,
                "name": "royal",
                "parent_id": 25,
                "position": "left",
                "depth": 3,
                "path": "3.24.25.34",
                "children": []
              }
            ]
          },
          {
            "id": 28,
            "name": "nico",
            "parent_id": 24,
            "position": "right",
            "depth": 2,
            "path": "3.24.28",
            "children": [
              {
                "id": 29,
                "name": "turner",
                "parent_id": 28,
                "position": "left",
                "depth": 3,
                "path": "3.24.28.29",
                "children": []
              }
            ]
          }
        ]
      },
      {
        "id": 26,
        "name": "joanie",
        "parent_id": 3,
        "position": "right",
        "depth": 1,
        "path": "3.26",
        "children": [
          {
            "id": 27,
            "name": "rick",
            "parent_id": 26,
            "position": "left",
            "depth": 2,
            "path": "3.26.27",
            "children": []
          },
          {
            "id": 30,
            "name": "feeney",
            "parent_id": 26,
            "position": "right",
            "depth": 2,
            "path": "3.26.30",
            "children": []
          }
        ]
      }
    ]
  }
]

I did try adding whereDepth(2) to the query.

It returns the parents in that depth but the children are empty array even though that parent has children.

$constraint = function ($query) use ($parentId) {
    $query->where('id', $parentId);
};

$tree = Account::query()
    ->treeOf($constraint)
    ->whereDepth(2) // added this
    ->get()
    ->toTree();

The query above returns the data below, notice that the children are an empty array even though that parent has children (see the complete data returned by $tree above).

[
  {
    "id": 25,
    "name": "brooks",
    "parent_id": 24,
    "position": "left",
    "depth": 2,
    "path": "3.24.25",
    "children": []
  },
  {
    "id": 28,
    "name": "nico",
    "parent_id": 24,
    "position": "right",
    "depth": 2,
    "path": "3.24.28",
    "children": []
  },
  {
    "id": 27,
    "name": "rick",
    "parent_id": 26,
    "position": "left",
    "depth": 2,
    "path": "3.26.27",
    "children": []
  },
  {
    "id": 30,
    "name": "feeney",
    "parent_id": 26,
    "position": "right",
    "depth": 2,
    "path": "3.26.30",
    "children": []
  }
]

Is there a way to get the parents for the given depth and also get the Level 1 children of those parents?

[staudenmeir]

Hi @whoami15,
toTree() "only" rearranges the query result. whereDepth(2) removes the children from the query result and that's why children is empty.

Try this instead:

$tree = Account::query()
    ->treeOf($constraint)
    ->whereDepth('>=', 2)
    ->whereDepth('<=', 3)
    ->get()
   ->toTree();

[whoami15]

Hi @staudenmeir

Thanks for the answer, I'll try this.