查询子级分类、父级分类、叶子节点分类（MySQL / Oracle ）

目录

• 查询当前分类及所有子级分类
• • MySQL
  • Oracle
• 查询当前分类及所有父级分类
• • Oracle
• 查询所有叶子节点分类
• • Oracle

查询当前分类及所有子级分类

MySQL

WITH RECURSIVE temp AS (
    -- 1.锚点查询（起始节点）
    SELECT
        c1.*
    FROM
        category c1
    WHERE c1.id = 1477358020655718400  -- 要查询的起始节点ID，存在多个时用IN
    
    UNION ALL
    
    -- 2.递归查询（关联子节点）
    SELECT
        c2.*
    FROM
        category c2
    INNER JOIN temp ON c2.parent_id = temp.id  -- 子节点的parent_id = 上一级节点的id
)
-- 3.输出所有子节点（包括起始节点本身，如需排除可加条件）
SELECT * FROM temp

Oracle

WITH temp(id) AS (
    -- 1.锚点查询（起始节点）
    SELECT
        c1.id
    FROM
        category c1
    WHERE
        c1.id = 1477358020655718400  -- 要查询的起始节点ID，存在多个时用IN
    
    UNION ALL
    
    -- 2.递归查询（关联子节点）
    SELECT
        c2.id
    FROM
        category c2, temp
    WHERE
        c2.parent_id = temp.id  -- 子节点的parent_id = 上一级节点的id
)
SELECT * FROM temp

查询当前分类及所有父级分类

Oracle

SELECT
    c.*
FROM
    category c
START WITH
    c.id = 1477358020655718400  -- 要查询的起始节点ID，存在多个时用IN
CONNECT BY PRIOR c.parent_id = c.id

查询所有叶子节点分类

Oracle

SELECT
    c4.*
FROM
    (
        SELECT
            c1.*
        FROM
            category c1
        START WITH
            c1.id = 1477358020655718400  -- 要查询的起始节点ID，存在多个时用IN
        CONNECT BY PRIOR c1.id = c1.parent_id
    ) c4
WHERE
    c4.id IN (
        SELECT
            c3.id
        FROM
            (
                SELECT
                    CONNECT_BY_ISLEAF,
                    c2.*
                FROM
                    category c2
                START WITH
                    c2.parent_id IS NULL
                CONNECT BY c2.parent_id = PRIOR id
            ) c3
        WHERE
            c3.CONNECT_BY_ISLEAF = 1
    )