Since one of my hobby is oversimplification, I was bored enough to write an anonymous code in javascript to make a hierarchycal tree node from a table.

var treeTable = [
	{ "id": 1, "parent": 0, "name": "Grandpa" }, 
	{ "id": 2, "parent": 1, "name": "Dad" }, 
	{ "id": 3, "parent": 1, "name": "Uncle" }, 
	{ "id": 4, "parent": 2, "name": "Me!" }, 
	{ "id": 5, "parent": 0, "name": "Grunkle" }, 
	{ "id": 6, "parent": 5, "name": "Cousin" }
]; // sample table...
var treeData = (function dataTree(input, parent = 0) {
	var ret = [];
	input.forEach(function(o, i) {
		if(o.parent == parent) {
			o.children = dataTree(input, o.id); // make the function recursive
			ret[ret.length] = o;
		}
	});
	return ret;
})(treeTable);
console.log(treeData);

/* outputs
	[
		{
			"id": 1, 
			"parent": 0, 
			"children": [
				{
					"id": 2, 
					"parent": 1, 
					"children": [
						{
							"id": 4, 
							"parent": 2,
							"children": []
						}
					]
				}, {
					"id": 3, 
					"parent": 1, 
					"children": []
				}
			]
		}, {
			"id": 5, 
			"parent": 0, 
			"children": [
				{
					"id": 6, 
					"parent": 5, 
					"children": []
				}
			]
		}
	]
*/

That's it. Or don't make it anonymous, depending on your use case.