将数据库查询结果数组转换为jsontreemakerjs数据时创建分层数组

假设我们有以下的数据库查询结果数组：

[ { "id": 1, "name": "Parent 1", "parent_id": null }, { "id": 2, "name": "Child 1", "parent_id": 1 }, { "id": 3, "name": "Child 2", "parent_id": 1 }, { "id": 4, "name": "Parent 2", "parent_id": null }, { "id": 5, "name": "Child 3", "parent_id": 4 }, { "id": 6, "name": "Child 4", "parent_id": 4 } ]

我们需要将其转换为以下格式：

[ { "text": "Parent 1", "nodes": [ { "text": "Child 1" }, { "text": "Child 2" } ] }, { "text": "Parent 2", "nodes": [ { "text": "Child 3" }, { "text": "Child 4" } ] } ]

我们可以使用以下代码来实现：

function makeTree(arr) { var tree = [], mappedArr = {}, arrElem, mappedElem;

// First map the nodes of the array to an object -> create a hash table. for(var i = 0, len = arr.length; i < len; i++) { arrElem = arr[i]; mappedArr[arrElem.id] = arrElem; mappedArr[arrElem.id]['nodes'] = []; }

for (var id in mappedArr) { if (mappedArr.hasOwnProperty(id)) { mappedElem = mappedArr[id]; // If the element is not at the root level, add it to its parent array of 'nodes'. if (mappedElem.parent_id) { mappedArr[mappedElem['parent_id']]['nodes'].push(mappedElem); } // If the element is at the