1bBmcxX2

1package main
2
3import (
4	"fmt"
5)
6
7/**
8 * DB structure if we use Mysql
9 DROP TABLE IF EXISTS `employees`;
10 CREATE TABLE `employees` (
11  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
12  `manager_id` int(10) unsigned DEFAULT NULL,
13  `name` varchar(512) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
14  `created_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP,
15  `updated_at` timestamp NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
16  PRIMARY KEY (`id`)
17) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
18*/
19
20/**
21 * Recursive sql if we using Mysql 8 +
22 * This will avoid printing out any unrelated employee
23WITH RECURSIVE EmployeeStuct AS (
24    SELECT * FROM employees WHERE manager_id IS NULL
25    UNION ALL
26    SELECT m.* FROM employees AS m JOIN EmployeeStuct AS t ON m.manager_id = t.id
27)
28SELECT * FROM EmployeeStuct;
29*/
30
31type Employee struct {
32	Id        int
33	ManagerId int
34	Name      string
35}
36type EmployeeTree struct {
37	Id        int
38	ManagerId int
39	Name      string
40	son       []EmployeeTree
41}
42
43var allEmployees = []Employee{
44	Employee{100, 150, "Alan"},
45	Employee{220, 100, "Martin"},
46	Employee{150, 0, "Jamie"},
47	Employee{275, 100, "Alex"},
48	Employee{400, 150, "Steve"},
49	Employee{190, 400, "David"},
50}
51
52func main() {
53	arr := recursiveTree(allEmployees, 0)
54	fmt.Println(arr)
55
56}
57
58// function to group the employees accordingly to their manager
59func recursiveTree(allEmployee []Employee, ManagerId int) []EmployeeTree {
60	var arr []EmployeeTree
61	for _, v := range allEmployee {
62		if ManagerId == v.ManagerId {
63			ctree := EmployeeTree{}
64			ctree.Id = v.Id
65			ctree.ManagerId = v.ManagerId
66			ctree.Name = v.Name
67
68			sonE := recursiveTree(allEmployee, v.Id)
69			ctree.son = sonE
70			arr = append(arr, ctree)
71		}
72	}
73	return arr
74}