golang递归实现类别树(CategoryTree)
2023-03-21 本文已影响0人
胡小毛
需求描述
点击一级或二级或三级类别都会进行查询，选中的类别变为紫色
效果图
数据库设计
model
// ArtAssetCategory 资产分类表 mapped from table <art_asset_category>
type ArtAssetCategory struct {
ID int32 `gorm:"column:id;primaryKey" json:"id"`
ParentID int32 `gorm:"column:parent_id;not null" json:"parent_id"` // 上级分类
Name string `gorm:"column:name;not null" json:"name"` // 分类名称
CreatedAt int64 `gorm:"column:created_at;autoCreateTime" json:"created_at"` // 创建日期
Remark string `gorm:"column:remark;not null" json:"remark"` // 备注
Order int32 `gorm:"column:order;not null" json:"order"` // 位置
}
表
实现思想
-
将根类别（ParentID为0）的类别装入 list
-
否则装入categoryMap（key：id，value：类别）
-
遍历 list，根据根类别 ID 从 categoryMap 中查出当前类别下的子类别
- 若一个类别的 ParentID == categroyId（list.id），则该类别为 categroyId(list.id) 下的子类别
- 将全部子类别装入 list
- 遍历 list，递归查询
-
根据order(位置)从小到大 排序
-
返回 包含子类别（Child）的类别树（CategoryTree）
golang代码实现
handler
// CategoryTree 所有分类 树形下拉接口
func (ah *ArtAssetHandler) CategoryTree(c *gin.Context) {
ctx := c.Request.Context()
resp, err := ah.artAssetLogic.AssetCategoryTree(ctx)
if err != nil {
ah.Fail(c, err)
return
}
ah.Success(c, resp)
}
logic
func (aal *ArtAssetLogic) AssetCategoryTree(ctx context.Context) (*bean.AssetCategoryTreeResp, error) {
alllist, err := aal.artAssetService.GetAllCategoryList(ctx)
if err != nil {
return nil, err
}
// 将根类别（ParentID为0）的类别装入list；
// 否则装入categoryMap（key：id，value：类别）
categoryMap := make(map[int32]*model.ArtAssetCategory)
list := make([]*model.ArtAssetCategory, 0) // 根级别 有可能是多个 所以是数组
for _, v := range alllist {
if v.ParentID == 0 { // 第一级别的列表 parentid ==0 默认0
list = append(list, v)
} else {
categoryMap[v.ID] = v
}
}
// 包含子类别（Child）的类别树（CategoryTree）
childList := make([]*bean.AssetCategoryTreeChild, 0, len(list))
for _, v := range list {
child := &bean.AssetCategoryTreeChild{
ID: v.ID,
Name: v.Name,
ParentId: v.ParentID,
Order: v.Order,
}
// 根据 ID 查出当前类别下的子类别
child.Child = aal.aggreCategoryTree(categoryMap, v.ID)
childList = append(childList, child)
}
// 根据order(位置)从小到大 排序
sort.Slice(childList, func(i, j int) bool {
return childList[i].Order < childList[j].Order
})
return &bean.AssetCategoryTreeResp{
Tree: childList,
}, nil
}
func (aal *ArtAssetLogic) aggreCategoryTree(cmap map[int32]*model.ArtAssetCategory, categroyId int32) []*bean.AssetCategoryTreeChild {
if categroyId <= 0 || len(cmap) <= 0 {
return nil
}
// 查询 categroyId 下的子类别
// 若一个类别的 ParentID == categroyId，则该类别为 categroyId 下的子类别
// 将全部子类别装入list
list := make([]*model.ArtAssetCategory, 0)
for _, v := range cmap {
if v.ParentID == categroyId { // 第一级别的列表
list = append(list, v)
}
}
if len(list) <= 0 {
return nil
}
// 包含子类别（Child）的类别树（CategoryTree）
childList := make([]*bean.AssetCategoryTreeChild, 0, len(list))
for _, v := range list {
child := &bean.AssetCategoryTreeChild{
ID: v.ID,
Name: v.Name,
ParentId: v.ParentID,
Order: v.Order,
}
// 根据 ID 查出当前类别下的子类别（递归）
sublist := aal.aggreCategoryTree(cmap, v.ID)
if sublist != nil && len(sublist) > 0 {
child.Child = sublist
}
childList = append(childList, child)
}
// 根据order(位置)从小到大 排序
sort.Slice(childList, func(i, j int) bool {
return childList[i].Order < childList[j].Order
})
return childList
}
service
// 获取资产分类 所有，内存做树形结构组装 只适合数量少的情况，数量大的一定让前端组装
func (aal *ArtAssetService) GetAllCategoryList(ctx context.Context) ([]*model.ArtAssetCategory, error) {
resList := make([]*model.ArtAssetCategory, 0)
db := gmysql.DB(ctx, config.GlobConfig.Mysql.DBName) //连接到数据库
categorys := query.Use(db).ArtAssetCategory
err := categorys.WithContext(ctx).Order(categorys.Order).Scan(&resList)
if err != nil {
return nil, err
}
return resList, nil
}
bean
type AssetCategoryTreeResp struct {
Tree []*AssetCategoryTreeChild `json:"list"`
}
type AssetCategoryTreeChild struct {
ID int32 `json:"id"`
Name string `json:"name"`
ParentId int32 `json:"parent_id"`
Child []*AssetCategoryTreeChild `json:"child"`
Order int32 `json:"order"`
}
请求结果
{
"code": 0,
"message": "",
"data": {
"list": [
{
"id": 1,
"name": "场景",
"parent_id": 0,
"child": [
{
"id": 9,
"name": "自然场景",
"parent_id": 1,
"child": null,
"order": 1
},
{
"id": 10,
"name": "建筑",
"parent_id": 1,
"child": null,
"order": 2
},
{
"id": 11,
"name": "地形",
"parent_id": 1,
"child": null,
"order": 3
},
{
"id": 12,
"name": "科技风",
"parent_id": 1,
"child": null,
"order": 4
},
{
"id": 13,
"name": "现代风",
"parent_id": 1,
"child": null,
"order": 5
},
{
"id": 14,
"name": "乡村风",
"parent_id": 1,
"child": null,
"order": 6
},
{
"id": 15,
"name": "场景部件",
"parent_id": 1,
"child": null,
"order": 7
},
{
"id": 16,
"name": "其他（场景）",
"parent_id": 1,
"child": null,
"order": 8
}
],
"order": 0
},
{
"id": 2,
"name": "人物",
"parent_id": 0,
"child": [
{
"id": 17,
"name": "成年人-男",
"parent_id": 2,
"child": null,
"order": 1
},
{
"id": 18,
"name": "成年人-女",
"parent_id": 2,
"child": null,
"order": 2
},
{
"id": 19,
"name": "孩子-男",
"parent_id": 2,
"child": null,
"order": 3
},
{
"id": 20,
"name": "孩子-女",
"parent_id": 2,
"child": null,
"order": 4
},
{
"id": 21,
"name": "老人-男",
"parent_id": 2,
"child": null,
"order": 5
},
{
"id": 22,
"name": "老人-女",
"parent_id": 2,
"child": null,
"order": 6
},
{
"id": 23,
"name": "其他（人物）",
"parent_id": 2,
"child": null,
"order": 7
}
],
"order": 1
},
{
"id": 3,
"name": "动物",
"parent_id": 0,
"child": [
{
"id": 24,
"name": "哺乳",
"parent_id": 3,
"child": null,
"order": 1
},
{
"id": 25,
"name": "飞禽",
"parent_id": 3,
"child": null,
"order": 2
},
{
"id": 26,
"name": "爬行",
"parent_id": 3,
"child": null,
"order": 3
},
{
"id": 27,
"name": "恐龙",
"parent_id": 3,
"child": null,
"order": 4
},
{
"id": 28,
"name": "昆虫",
"parent_id": 3,
"child": null,
"order": 5
},
{
"id": 29,
"name": "鱼类",
"parent_id": 3,
"child": null,
"order": 6
},
{
"id": 30,
"name": "两栖",
"parent_id": 3,
"child": null,
"order": 7
},
{
"id": 31,
"name": "机器动物",
"parent_id": 3,
"child": null,
"order": 8
},
{
"id": 32,
"name": "其他（动物）",
"parent_id": 3,
"child": null,
"order": 9
}
],
"order": 2
},
{
"id": 4,
"name": "植物",
"parent_id": 0,
"child": [
{
"id": 33,
"name": "石头",
"parent_id": 4,
"child": null,
"order": 1
},
{
"id": 34,
"name": "花卉",
"parent_id": 4,
"child": null,
"order": 2
},
{
"id": 35,
"name": "树木",
"parent_id": 4,
"child": null,
"order": 3
},
{
"id": 36,
"name": "草类",
"parent_id": 4,
"child": null,
"order": 4
},
{
"id": 37,
"name": "水果蔬菜",
"parent_id": 4,
"child": null,
"order": 5
},
{
"id": 38,
"name": "其他（植物）",
"parent_id": 4,
"child": null,
"order": 6
}
],
"order": 3
},
{
"id": 5,
"name": "道具",
"parent_id": 0,
"child": [
{
"id": 39,
"name": "武器",
"parent_id": 5,
"child": null,
"order": 1
},
{
"id": 40,
"name": "家具/生活用具",
"parent_id": 5,
"child": [
{
"id": 49,
"name": "沙发",
"parent_id": 40,
"child": null,
"order": 1
},
{
"id": 50,
"name": "桌椅",
"parent_id": 40,
"child": null,
"order": 2
},
{
"id": 51,
"name": "床",
"parent_id": 40,
"child": null,
"order": 3
},
{
"id": 52,
"name": "柜子",
"parent_id": 40,
"child": null,
"order": 4
},
{
"id": 53,
"name": "门窗",
"parent_id": 40,
"child": null,
"order": 5
},
{
"id": 54,
"name": "灯具",
"parent_id": 40,
"child": null,
"order": 6
}
],
"order": 2
},
{
"id": 41,
"name": "食品/饮料/药品",
"parent_id": 5,
"child": [
{
"id": 55,
"name": "水果",
"parent_id": 41,
"child": null,
"order": 1
},
{
"id": 56,
"name": "蔬菜",
"parent_id": 41,
"child": null,
"order": 2
},
{
"id": 57,
"name": "零食",
"parent_id": 41,
"child": null,
"order": 3
},
{
"id": 58,
"name": "饮料",
"parent_id": 41,
"child": null,
"order": 4
}
],
"order": 3
},
{
"id": 42,
"name": "其他（道具）",
"parent_id": 5,
"child": null,
"order": 4
}
],
"order": 4
},
{
"id": 6,
"name": "载具",
"parent_id": 0,
"child": [
{
"id": 43,
"name": "车辆",
"parent_id": 6,
"child": null,
"order": 1
},
{
"id": 44,
"name": "船艇",
"parent_id": 6,
"child": null,
"order": 2
},
{
"id": 45,
"name": "飞机/航空器",
"parent_id": 6,
"child": null,
"order": 3
},
{
"id": 46,
"name": "其他（载具）",
"parent_id": 6,
"child": null,
"order": 4
}
],
"order": 5
},
{
"id": 7,
"name": "怪物",
"parent_id": 0,
"child": [
{
"id": 47,
"name": "其他（怪物）",
"parent_id": 7,
"child": null,
"order": 0
}
],
"order": 6
},
{
"id": 8,
"name": "其他",
"parent_id": 0,
"child": [
{
"id": 48,
"name": "其他（其他）",
"parent_id": 8,
"child": null,
"order": 0
}
],
"order": 7
}
]
}
}
