sqlsugar 树型递归查询。UtilMethods.BuildTree 用法

sqlsugar 树型递归查询官方文档：
https://www.donet5.com/home/doc?masterId=1&typeId=2311

UtilMethods.BuildTree 用法

public class Tree
{
    [SqlSugar.SugarColumn(IsPrimaryKey = true)]
    public int Id { get; set; }
    public string Name { get; set; }
    public int ParentId { get; set; }
    public List<Tree> Child { get; set; }
}
// 假设已经从数据库查询得到一个Tree实体的列表list
var tree = UtilMethods.BuildTree(db, list, "Id", "ParentId", "Child", 0);