Truy vấn MySQL - phân tích dữ liệu bằng cách sử dụng tên URL nơi dữ liệu được tổ chức thành một hệ thống phân cấp

Điều này có thể thực hiện được nếu DBMS của bạn hỗ trợ các truy vấn đệ quy:

DROP SCHEMA tmp CASCADE;
CREATE SCHEMA tmp ;

CREATE TABLE tmp.webmeuk
    ( id INTEGER NOT NULL PRIMARY KEY
    , slug VARCHAR
    , content_type_id INTEGER NOT NULL
    , parent_id INTEGER REFERENCES tmp.webmeuk(id)
    );
INSERT INTO tmp.webmeuk( id , slug, content_type_id , parent_id )
VALUES(  0 , 'HTTP://pr0n.mysite.xx',    5 , NULL )
    , (  1 , 'portfolio',   5 , 0 )
    , (  2 , 'about-us',    1 , 0 )
    , (  3 , 'find-us',     1 , 0 )
    , (  4 , 'contact-us',  1 , 2 )
    , (  5 , 'find-us',     1 , 4 )
    ;

-- a room with a view
CREATE VIEW tmp.reteview AS (
    WITH RECURSIVE xx AS (
        SELECT w0.id AS id
        , w0.slug AS slug
        , w0.content_type_id AS content_type_id
        , w0.slug AS fullpath
        FROM tmp.webmeuk w0
        WHERE w0.parent_id IS NULL
      UNION 
        SELECT w1.id AS id
        , w1.slug AS slug
        , w1.content_type_id AS content_type_id
        , xx.fullpath || '/'::text || w1.slug AS fullpath
        FROM tmp.webmeuk w1, xx
        WHERE w1.parent_id = xx.id
        )
    SELECT * FROM xx
    );

SELECT * FROM tmp.reteview ;

-- Change one row of data
UPDATE tmp.webmeuk
SET slug = 'what-about-us'
WHERE id = 2;

SELECT * FROM tmp.reteview ;

Đầu ra:

NOTICE:  drop cascades to 2 other objects
DETAIL:  drop cascades to table tmp.webmeuk
drop cascades to view tmp.closure
DROP SCHEMA
CREATE SCHEMA
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "webmeuk_pkey" for table "webmeuk"
CREATE TABLE
INSERT 0 6
CREATE VIEW
 id |         slug          | content_type_id |                     fullpath                  
----+-----------------------+-----------------+---------------------------------------------------
  0 | HTTP://pr0n.mysite.xx |               5 | HTTP://pr0n.mysite.xx
  1 | portfolio             |               5 | HTTP://pr0n.mysite.xx/portfolio
  2 | about-us              |               1 | HTTP://pr0n.mysite.xx/about-us
  3 | find-us               |               1 | HTTP://pr0n.mysite.xx/find-us
  4 | contact-us            |               1 | HTTP://pr0n.mysite.xx/about-us/contact-us
  5 | find-us               |               1 | HTTP://pr0n.mysite.xx/about-us/contact-us/find-us
(6 rows)

UPDATE 1
 id |         slug          | content_type_id |                        fullpath                    
----+-----------------------+-----------------+--------------------------------------------------------
  0 | HTTP://pr0n.mysite.xx |               5 | HTTP://pr0n.mysite.xx
  1 | portfolio             |               5 | HTTP://pr0n.mysite.xx/portfolio
  3 | find-us               |               1 | HTTP://pr0n.mysite.xx/find-us
  2 | what-about-us         |               1 | HTTP://pr0n.mysite.xx/what-about-us
  4 | contact-us            |               1 | HTTP://pr0n.mysite.xx/what-about-us/contact-us
  5 | find-us               |               1 | HTTP://pr0n.mysite.xx/what-about-us/contact-us/find-us
(6 rows)