make a nameless array out 2 diferent tables with children in php

Question

I have 2 tables in my DB. 1 is full with numbers (foreign keys) and other one is full of the data I need. This is how the array should (exactly) look

"array" : [
    {
        "data" : "blabla"
        "data2" : "blabla"
        "children" : [
            {
                "data" : "blabla"
                "data2" : "blabla" 
                "children" : [
                    {
                        "data" : "blabla"
                        "data2" : "blabla" 
                    }
                ]
            },
            {
                "data" : "blabla"
                "data2" : "blabla" 
                "children" : [
                    {
                        "data" : "blabla"
                        "data2" : "blabla" 
                    }
                ]
            }
        ]
    }
]

and so on, so to say.. now the right order you can find in table 1,where it is lited what the mother ID is. and i need to get the data out of table 2 so be in the array. anyone knows how to do this? i am working in codeigniter

updated with pics:

wanted to add that in theory, the amount of childs could be/should be endless — Sven Elmendorp, Aug 28 '18 at 13:13
Can you post the structure of your two tables in a more direct manner ? It would help greatly. — linkboss, Aug 28 '18 at 13:14

score 1 · Accepted Answer · answered Aug 28 '18 at 13:41

1

To do that, you would need to process in two steps:

You fetch each document and it's data from the two tables (let's call them "documents" and "documents_data" to build a flat array of all the documents. This way you don't have to wonder where does the data go anymore :
```
$results = $this->db->query("SELECT d.*, dd.* FROM documents d LEFT JOIN documents_data dd ON dd.doc_id = d.doc_id");
$documents = $results->result_array();
```

Now that we have everything about each document, we just need to reorder them in a recursive array using a recursive function, that will call itself with the parent id for each children and build the tree :

function getDocumentTree($documents, $idParent = null)
{
    $tree = [];

    foreach($documents as $document) {
        if($document['doc_doc_id'] == $idParent) {
            $document['children'] = getDocumentTree($documents, $document['doc_id']);
            $tree[] = $document;
        }
    }

    return $tree;
}

$tree = getDocumentTree($documents);

Note: I haven't tested this code, this is just an idea on how it works, try to understand that (especially the concept of recursivity) and implement it by yourself.

answered Aug 28 '18 at 13:41

linkboss

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thanks for your answer, i will try this out right away – Sven Elmendorp Aug 28 '18 at 13:46
hey, i tried out your code. i gotten the following error – Sven Elmendorp Aug 28 '18 at 13:59
Maximum function nesting level of '256' reached, aborting! – Sven Elmendorp Aug 28 '18 at 13:59
should add that i did dit it according to my own data – Sven Elmendorp Aug 28 '18 at 14:08
This denotes an infinite recursion. I just tested my code on a flat array of data, and it works as expected. Are you using it on massive amount of recursive data ? If not, maybe try to check what the first part (fetching the elements from the database) returns as array and try to work out the tree structure yourself, maybe there's a cyclical reference in the documents (which is something that can happen). – linkboss Aug 28 '18 at 14:09
yeah, the table has over 150 rows, and supposivly increasing – Sven Elmendorp Aug 28 '18 at 14:13
i fixed it based on your code, but changin ithere and there. and also changing the query to the DB – Sven Elmendorp Aug 29 '18 at 08:35
Nice, I hope you understood how it works, that's the essential. – linkboss Aug 29 '18 at 10:26

make a nameless array out 2 diferent tables with children in php

1 Answers1