Question

我有一个具有此结构的sqlite数据库

create table categories
                ( CategoryID       integer     not null  primary key
                , CategoryName     text not null
                , CategoryParentID integer     null
                ,FOREIGN KEY (CategoryParentID) REFERENCES categories(CategoryID)
                );

根据父ID，我想拥有n级的所有后代（作为树），但我不知道该怎么做。真的很感谢你的帮助。

我已经有类似的东西，但我不知道在哪里放置父ID条件来开始搜索

WITH RECURSIVE cte_categories (categorias.CategoryID, categorias.CategoryName, categorias.CategoryParentID, depth) AS (
SELECT categorias.CategoryID, categorias.CategoryName, categorias.CategoryParentID, 1
FROM categorias
WHERE categorias.CategoryParentID IS NULL 
UNION ALL
SELECT c.CategoryID, c.CategoryName, c.CategoryParentID, r.depth + 1
FROM categories AS c
INNER JOIN cte_categories AS r ON (c.CategoryParentID = r.CategoryID)
)
SELECT CategoryName, depth, CategoryParentID
FROM cte_categories ORDER BY depth, CategoryName;

给定父ID的递归sqlite查询

0 个答案: