Populating a tree from a flat table of [sub]categories
(1) By Pierre-Yves Delens (PyDelens) on 2021-07-19 10:49:18 [link] [source]
Hello, please see below table definition and datas. From this flat table I need to display (in HTML, out of scope here) a tree of Categories. At each level (3 of them, not more) the sorting discriminant is PgSort At top level, by design ParentPage_Id is NULL At 2d level ParentPage_Id is NOT NULL, but parent of parent is NULL At 3d level, the item has 2 ancestors I had some trials, with calculated fields, but I'll have to nest queries, or Window Functions. A long time ago, i implemented this successfully in Access/VBA, but I think I need some help. (I didn't practise SQL for some years, I'm back) Output to be kind of : _____________________________ PgPost / PgPost / PgPost 10 10-10 10-20 10-20-10 10-20-25 10-30 10-30-10 10-30-15 10-30-35 20 20-05 20-05-10 20-05-15 _______________________________ Can someone give me just a hint, nudge, good example of nested queries or window function...? Thanks on forward. Pierre-Yves Delens (.be) CREATE TABLE "PagesTreeTT1" ( "ID_Page" INTEGER, "TxtID_Page" TEXT(25) NOT NULL, "ParentPage_Id" INTEGER, "PgSlug" TEXT(120) NOT NULL, "PgDescr" TEXT(200), "PgSort" integer(2) DEFAULT 50, PRIMARY KEY ("ID_Page") ); sqlite> SELECT * FROM PagesTreeTT1; +---------+-------------+---------------+--------+----------------------------+--------+ | ID_Page | TxtID_Page | ParentPage_Id | PgSlug | PgDescr | PgSort | +---------+-------------+---------------+--------+----------------------------+--------+ | 2 | HistRchch | NULL | h | Histoire d'une recherche | 10 | | 3 | TrvLieu | NULL | t | Trouver un lieu | 10 | | 4 | GDN_ | 2 | g | Gedinne - et rien d'autre | 20 | | 5 | gTrv | 2 | j | J'ai trouvé | 30 | | 6 | dots | 2 | . | ... | 40 | | 7 | decouvert | 2 | d | Découverte | 20 | | 8 | testAccent1 | NULL | a | aaa éàçè | 10 | | 9 | testAccent2 | 7 | b | bbb &$^~ | 20 | | 10 | SsLaForge | 7 | s | Sous la Forge - Copinette- | 30 | | 11 | inaug | 7 | i | Inauguration | 40 | | 12 | chantier_ | NULL | u | Un chantier? | 50 | | 13 | autour | NULL | e | Et autour de ce site | 60 | | 14 | infos | NULL | ii | Infos utiles | 70 | | 15 | WillVlg | 14 | w | Willerzie (village) | 10 | | 16 | GdnCmn | 14 | gg | Gedinne (Commune) | 20 | | 17 | commerces | 14 | c | Commerces | 30 | | 18 | services | 14 | s | Services | 40 | | 19 | VieLocale- | 14 | v | Vie locale et régionale | 50 | | 20 | SocioEco | 19 | ss | Socio-économie | 10 | | 21 | culturel | 19 | cc | Culturel | 20 | | 22 | politik | 19 | p | Politique | 30 | | 23 | patrimn | 19 | pp | Patrimoine | 40 | | 24 | nature | 19 | n | Nature | 50 | | 25 | about | NULL | a | A propos | 95 | | 26 | hebergt | 18 | hh | Hébergements | 10 | | 27 | restaur | 18 | r | Restauration | 20 | | 28 | SportAct | 18 | sa | Sports - Activités | 30 | | 29 | brol | 18 | bb | brol | 35 | | 30 | bril | 18 | bbb | bril | 36 | +---------+-------------+---------------+--------+----------------------------+--------+
(2) By ddevienne on 2021-07-19 12:11:45 in reply to 1 [source]
Start with https://www.sqlite.org/lang_with.html
But could be done with a 3-way join too, since you explicitly want to do 3 levels only.
(4) By Pierre-Yves Delens (PyDelens) on 2021-07-20 08:00:08 in reply to 2 [link] [source]
What a welcome on this forum! :-) Already big thanks to both of you. Very very helpful, .. just need some time to digest this (which is a key issue in my projects). Yours,
(3) By Ryan Smith (cuz) on 2021-07-19 12:52:57 in reply to 1 [link] [source]
It is quite hard to match that exact output structure, plus I'm not sure if you were just lazy when making the example or I am understanding it wrong, but the tree data does not evaluate to your example. I will accept your statement of "...to be kind of:" to mean that you were not being accurate.
That said, here is a script that achieves it (final query below) if my understanding of your request is correct. If it isn't, please say how exactly and give an example that displays accurate logic.
Since you indicated wanting to learn and not simply have a result - I have included several interim queries (including some unnecessary fields) to show what each step of the final query's CTE achieves. Please ask if anything is unclear, and good luck!
-- SQLite version 3.35.4 [ Release: 2021-04-02 ] on SQLitespeed version 2.1.3.11.
-- ================================================================================
CREATE TABLE "PagesTreeTT1" (
"ID_Page" INTEGER,
"TxtID_Page" TEXT(25) NOT NULL,
"ParentPage_Id" INTEGER,
"PgSlug" TEXT(120) NOT NULL,
"PgDescr" TEXT(200),
"PgSort" integer(2) DEFAULT 50,
PRIMARY KEY ("ID_Page")
);
INSERT INTO PagesTreeTT1(ID_Page, TxtID_Page, ParentPage_Id, PgSlug, PgDescr, PgSort) VALUES
( 2, 'HistRchch ' , NULL , 'h' , 'Histoire d''une recherche' , 10 )
,( 3, 'TrvLieu ' , NULL , 't' , 'Trouver un lieu' , 10 )
,( 4, 'GDN_ ' , 2 , 'g' , 'Gedinne - et rien d''autre' , 20 )
,( 5, 'gTrv ' , 2 , 'j' , 'J''ai trouvé' , 30 )
,( 6, 'dots ' , 2 , '.' , '...' , 40 )
,( 7, 'decouvert ' , 2 , 'd' , 'Découverte' , 20 )
,( 8, 'testAccent1' , NULL , 'a' , 'aaa éàçè' , 10 )
,( 9, 'testAccent2' , 7 , 'b' , 'bbb &$^~' , 20 )
,( 10, 'SsLaForge ' , 7 , 's' , 'Sous la Forge - Copinette-' , 30 )
,( 11, 'inaug ' , 7 , 'i' , 'Inauguration' , 40 )
,( 12, 'chantier_ ' , NULL , 'u' , 'Un chantier?' , 50 )
,( 13, 'autour ' , NULL , 'e' , 'Et autour de ce site' , 60 )
,( 14, 'infos ' , NULL , 'ii' , 'Infos utiles' , 70 )
,( 15, 'WillVlg ' , 14 , 'w' , 'Willerzie (village)' , 10 )
,( 16, 'GdnCmn ' , 14 , 'gg' , 'Gedinne (Commune)' , 20 )
,( 17, 'commerces ' , 14 , 'c' , 'Commerces' , 30 )
,( 18, 'services ' , 14 , 's' , 'Services' , 40 )
,( 19, 'VieLocale- ' , 14 , 'v' , 'Vie locale et régionale' , 50 )
,( 20, 'SocioEco ' , 19 , 'ss' , 'Socio-économie' , 10 )
,( 21, 'culturel ' , 19 , 'cc' , 'Culturel' , 20 )
,( 22, 'politik ' , 19 , 'p' , 'Politique' , 30 )
,( 23, 'patrimn ' , 19 , 'pp' , 'Patrimoine' , 40 )
,( 24, 'nature ' , 19 , 'n' , 'Nature' , 50 )
,( 25, 'about ' , NULL , 'a' , 'A propos' , 95 )
,( 26, 'hebergt ' , 18 , 'hh' , 'Hébergements' , 10 )
,( 27, 'restaur ' , 18 , 'r' , 'Restauration' , 20 )
,( 28, 'SportAct ' , 18 , 'sa' , 'Sports - Activités' , 30 )
,( 29, 'brol ' , 18 , 'bb' , 'brol' , 35 )
,( 30, 'bril ' , 18 , 'bbb', 'bril' , 36 )
SELECT *
FROM PagesTreeTT1
;
-- | |ParentPa-| | |
-- ID_Page |TxtID_Page |ge_Id |PgSlug|PgDescr |PgSort
-- ------------|-------------|---------|------|----------------------------|------
-- 2 |HistRchch |NULL | h |Histoire d'une recherche | 10
-- 3 |TrvLieu |NULL | t |Trouver un lieu | 10
-- 4 |GDN_ |2 | g |Gedinne - et rien d'autre | 20
-- 5 |gTrv |2 | j |J'ai trouvé | 30
-- 6 |dots |2 | . |... | 40
-- 7 |decouvert |2 | d |Découverte | 20
-- 8 |testAccent1 |NULL | a |aaa éàçè | 10
-- 9 |testAccent2 |7 | b |bbb &$^~ | 20
-- 10 |SsLaForge |7 | s |Sous la Forge - Copinette- | 30
-- 11 |inaug |7 | i |Inauguration | 40
-- 12 |chantier_ |NULL | u |Un chantier? | 50
-- 13 |autour |NULL | e |Et autour de ce site | 60
-- 14 |infos |NULL | ii |Infos utiles | 70
-- 15 |WillVlg |14 | w |Willerzie (village) | 10
-- 16 |GdnCmn |14 | gg |Gedinne (Commune) | 20
-- 17 |commerces |14 | c |Commerces | 30
-- 18 |services |14 | s |Services | 40
-- 19 |VieLocale- |14 | v |Vie locale et régionale | 50
-- 20 |SocioEco |19 | ss |Socio-économie | 10
-- 21 |culturel |19 | cc |Culturel | 20
-- 22 |politik |19 | p |Politique | 30
-- 23 |patrimn |19 | pp |Patrimoine | 40
-- 24 |nature |19 | n |Nature | 50
-- 25 |about |NULL | a |A propos | 95
-- 26 |hebergt |18 | hh |Hébergements | 10
-- 27 |restaur |18 | r |Restauration | 20
-- 28 |SportAct |18 | sa |Sports - Activités | 30
-- 29 |brol |18 | bb |brol | 35
-- 30 |bril |18 | bbb |bril | 36
WITH CT(id, pid, lvl, srt, pgName) AS (
SELECT ID_Page, ParentPage_Id, 0, PgSort, TxtID_Page
FROM PagesTreeTT1
WHERE ParentPage_Id IS NULL
UNION ALL
SELECT ID_Page, ParentPage_Id, lvl+1, PgSort, TxtID_Page
FROM CT
JOIN PagesTreeTT1 AS P
WHERE P.ParentPage_Id = CT.id LIMIT 1000
)
SELECT *
FROM CT
-- id |pid |lvl| srt|pgName
-- ----|------|---|----|-------------
-- 2 |NULL | 0 | 10 |HistRchch
-- 3 |NULL | 0 | 10 |TrvLieu
-- 8 |NULL | 0 | 10 |testAccent1
-- 12 |NULL | 0 | 50 |chantier_
-- 13 |NULL | 0 | 60 |autour
-- 14 |NULL | 0 | 70 |infos
-- 25 |NULL | 0 | 95 |about
-- 4 |2 | 1 | 20 |GDN_
-- 7 |2 | 1 | 20 |decouvert
-- 6 |2 | 1 | 40 |dots
-- 5 |2 | 1 | 30 |gTrv
-- 16 |14 | 1 | 20 |GdnCmn
-- 19 |14 | 1 | 50 |VieLocale-
-- 15 |14 | 1 | 10 |WillVlg
-- 17 |14 | 1 | 30 |commerces
-- 18 |14 | 1 | 40 |services
-- 10 |7 | 2 | 30 |SsLaForge
-- 11 |7 | 2 | 40 |inaug
-- 9 |7 | 2 | 20 |testAccent2
-- 20 |19 | 2 | 10 |SocioEco
-- 21 |19 | 2 | 20 |culturel
-- 24 |19 | 2 | 50 |nature
-- 23 |19 | 2 | 40 |patrimn
-- 22 |19 | 2 | 30 |politik
-- 28 |18 | 2 | 30 |SportAct
-- 30 |18 | 2 | 36 |bril
-- 29 |18 | 2 | 35 |brol
-- 26 |18 | 2 | 10 |hebergt
-- 27 |18 | 2 | 20 |restaur
WITH CT(id, pid, lvl, srt, pgName) AS (
SELECT ID_Page, ParentPage_Id, 0, PgSort, TxtID_Page
FROM PagesTreeTT1
WHERE ParentPage_Id IS NULL
UNION ALL
SELECT ID_Page, ParentPage_Id, lvl+1, PgSort, TxtID_Page
FROM CT
JOIN PagesTreeTT1 AS P
WHERE P.ParentPage_Id = CT.id LIMIT 1000
)
SELECT CTLvl0.id, CTLvl0.pid, CTLvl0.lvl, CTLvl0.srt, CTLvl0.pgName,
null, null, null, null, null,
null, null, null, null, null
FROM CT AS CTLvl0
WHERE CTLvl0.lvl = 0
UNION ALL
SELECT CTLvl0.id, CTLvl0.pid, CTLvl0.lvl, CTLvl0.srt, CTLvl0.pgName,
CTLvl1.id, CTLvl1.pid, CTLvl1.lvl, CTLvl1.srt, CTLvl1.pgName,
null, null, null, null, null
FROM CT AS CTLvl0
JOIN CT AS CTLvl1 ON CTLvl1.pid = CTLvl0.id
WHERE CTLvl0.lvl = 0 AND CTLvl1.lvl = 1
UNION ALL
SELECT CTLvl0.id, CTLvl0.pid, CTLvl0.lvl, CTLvl0.srt, CTLvl0.pgName,
CTLvl1.id, CTLvl1.pid, CTLvl1.lvl, CTLvl1.srt, CTLvl1.pgName,
CTLvl2.id, CTLvl2.pid, CTLvl2.lvl, CTLvl2.srt, CTLvl2.pgName
FROM CT AS CTLvl0
JOIN CT AS CTLvl1 ON CTLvl1.pid = CTLvl0.id
JOIN CT AS CTLvl2 ON CTLvl2.pid = CTLvl1.id
WHERE CTLvl0.lvl = 0 AND CTLvl1.lvl = 1 AND CTLvl2.lvl = 2
-- id |pid |lvl| srt|pgName |null |null |null |null |null |null |null |null |null |null
-- ----|------|---|----|-------------|------|------|------|------|-------------|------|------|------|------|-------------
-- 2 |NULL | 0 | 10 |HistRchch |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL
-- 3 |NULL | 0 | 10 |TrvLieu |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL
-- 8 |NULL | 0 | 10 |testAccent1 |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL
-- 12 |NULL | 0 | 50 |chantier_ |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL
-- 13 |NULL | 0 | 60 |autour |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL
-- 14 |NULL | 0 | 70 |infos |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL
-- 25 |NULL | 0 | 95 |about |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL |NULL
-- 2 |NULL | 0 | 10 |HistRchch |4 |2 |1 |20 |GDN_ |NULL |NULL |NULL |NULL |NULL
-- 2 |NULL | 0 | 10 |HistRchch |5 |2 |1 |30 |gTrv |NULL |NULL |NULL |NULL |NULL
-- 2 |NULL | 0 | 10 |HistRchch |6 |2 |1 |40 |dots |NULL |NULL |NULL |NULL |NULL
-- 2 |NULL | 0 | 10 |HistRchch |7 |2 |1 |20 |decouvert |NULL |NULL |NULL |NULL |NULL
-- 14 |NULL | 0 | 70 |infos |15 |14 |1 |10 |WillVlg |NULL |NULL |NULL |NULL |NULL
-- 14 |NULL | 0 | 70 |infos |16 |14 |1 |20 |GdnCmn |NULL |NULL |NULL |NULL |NULL
-- 14 |NULL | 0 | 70 |infos |17 |14 |1 |30 |commerces |NULL |NULL |NULL |NULL |NULL
-- 14 |NULL | 0 | 70 |infos |18 |14 |1 |40 |services |NULL |NULL |NULL |NULL |NULL
-- 14 |NULL | 0 | 70 |infos |19 |14 |1 |50 |VieLocale- |NULL |NULL |NULL |NULL |NULL
-- 2 |NULL | 0 | 10 |HistRchch |7 |2 |1 |20 |decouvert |10 |7 |2 |30 |SsLaForge
-- 2 |NULL | 0 | 10 |HistRchch |7 |2 |1 |20 |decouvert |11 |7 |2 |40 |inaug
-- 2 |NULL | 0 | 10 |HistRchch |7 |2 |1 |20 |decouvert |9 |7 |2 |20 |testAccent2
-- 14 |NULL | 0 | 70 |infos |19 |14 |1 |50 |VieLocale- |20 |19 |2 |10 |SocioEco
-- 14 |NULL | 0 | 70 |infos |19 |14 |1 |50 |VieLocale- |21 |19 |2 |20 |culturel
-- 14 |NULL | 0 | 70 |infos |19 |14 |1 |50 |VieLocale- |24 |19 |2 |50 |nature
-- 14 |NULL | 0 | 70 |infos |19 |14 |1 |50 |VieLocale- |23 |19 |2 |40 |patrimn
-- 14 |NULL | 0 | 70 |infos |19 |14 |1 |50 |VieLocale- |22 |19 |2 |30 |politik
-- 14 |NULL | 0 | 70 |infos |18 |14 |1 |40 |services |28 |18 |2 |30 |SportAct
-- 14 |NULL | 0 | 70 |infos |18 |14 |1 |40 |services |30 |18 |2 |36 |bril
-- 14 |NULL | 0 | 70 |infos |18 |14 |1 |40 |services |29 |18 |2 |35 |brol
-- 14 |NULL | 0 | 70 |infos |18 |14 |1 |40 |services |26 |18 |2 |10 |hebergt
-- 14 |NULL | 0 | 70 |infos |18 |14 |1 |40 |services |27 |18 |2 |20 |restaur
WITH CT(id, pid, lvl, srt, pgName) AS (
SELECT ID_Page, ParentPage_Id, 0, PgSort, TxtID_Page
FROM PagesTreeTT1
WHERE ParentPage_Id IS NULL
UNION ALL
SELECT ID_Page, ParentPage_Id, lvl+1, PgSort, TxtID_Page
FROM CT
JOIN PagesTreeTT1 AS P
WHERE P.ParentPage_Id = CT.id LIMIT 1000
), PT(PgPostA, PgPostB, PgPostC) AS (
SELECT CTLvl0.srt, null, null
FROM CT AS CTLvl0
WHERE CTLvl0.lvl = 0
UNION ALL
SELECT CTLvl0.srt, CTLvl0.srt||'-'||CTLvl1.srt, null
FROM CT AS CTLvl0
JOIN CT AS CTLvl1 ON CTLvl1.pid = CTLvl0.id
WHERE CTLvl0.lvl = 0 AND CTLvl1.lvl = 1
UNION ALL
SELECT CTLvl0.srt, CTLvl0.srt||'-'||CTLvl1.srt, CTLvl0.srt||'-'||CTLvl1.srt||'-'||CTLvl2.srt
FROM CT AS CTLvl0
JOIN CT AS CTLvl1 ON CTLvl1.pid = CTLvl0.id
JOIN CT AS CTLvl2 ON CTLvl2.pid = CTLvl1.id
WHERE CTLvl0.lvl = 0 AND CTLvl1.lvl = 1 AND CTLvl2.lvl = 2
)
SELECT DISTINCT PgPostA,PgPostB,PgPostC
FROM PT
ORDER BY PgPostA,PgPostB,PgPostC
-- PgPostA|PgPostB|PgPostC
-- -------|-------|----------
-- 10 |NULL |NULL
-- 10 |10-20 |NULL
-- 10 |10-20 |10-20-20
-- 10 |10-20 |10-20-30
-- 10 |10-20 |10-20-40
-- 10 |10-30 |NULL
-- 10 |10-40 |NULL
-- 50 |NULL |NULL
-- 60 |NULL |NULL
-- 70 |NULL |NULL
-- 70 |70-10 |NULL
-- 70 |70-20 |NULL
-- 70 |70-30 |NULL
-- 70 |70-40 |NULL
-- 70 |70-40 |70-40-10
-- 70 |70-40 |70-40-20
-- 70 |70-40 |70-40-30
-- 70 |70-40 |70-40-35
-- 70 |70-40 |70-40-36
-- 70 |70-50 |NULL
-- 70 |70-50 |70-50-10
-- 70 |70-50 |70-50-20
-- 70 |70-50 |70-50-30
-- 70 |70-50 |70-50-40
-- 70 |70-50 |70-50-50
-- 95 |NULL |NULL
WITH CT(id, pid, lvl, srt, pgName) AS (
SELECT ID_Page, ParentPage_Id, 0, PgSort, TxtID_Page
FROM PagesTreeTT1
WHERE ParentPage_Id IS NULL
UNION ALL
SELECT ID_Page, ParentPage_Id, lvl+1, PgSort, TxtID_Page
FROM CT
JOIN PagesTreeTT1 AS P
WHERE P.ParentPage_Id = CT.id LIMIT 1000
), PT(PgPostA, PgPostB, PgPostC) AS (
SELECT CTLvl0.srt, null, null
FROM CT AS CTLvl0
WHERE CTLvl0.lvl = 0
UNION ALL
SELECT CTLvl0.srt, CTLvl0.srt||'-'||CTLvl1.srt, null
FROM CT AS CTLvl0
JOIN CT AS CTLvl1 ON CTLvl1.pid = CTLvl0.id
WHERE CTLvl0.lvl = 0 AND CTLvl1.lvl = 1
UNION ALL
SELECT CTLvl0.srt, CTLvl0.srt||'-'||CTLvl1.srt, CTLvl0.srt||'-'||CTLvl1.srt||'-'||CTLvl2.srt
FROM CT AS CTLvl0
JOIN CT AS CTLvl1 ON CTLvl1.pid = CTLvl0.id
JOIN CT AS CTLvl2 ON CTLvl2.pid = CTLvl1.id
WHERE CTLvl0.lvl = 0 AND CTLvl1.lvl = 1 AND CTLvl2.lvl = 2
), DT(PgPostA, PgPostB, PgPostC) AS (
SELECT DISTINCT
CASE WHEN PgPostB IS NULL THEN IFNULL(PgPostA,'') ELSE '' END,
CASE WHEN PgPostC IS NULL THEN IFNULL(PgPostB,'') ELSE '' END,
IFNULL(PgPostC,'')
FROM PT
ORDER BY PgPostA,PgPostB,PgPostC
)
SELECT PgPostA, PgPostB, PgPostC
FROM DT
;
-- PgPostA|PgPostB|PgPostC
-- -------|-------|----------
-- 10 | |
-- |10-20 |
-- | |10-20-20
-- | |10-20-30
-- | |10-20-40
-- |10-30 |
-- |10-40 |
-- 50 | |
-- 60 | |
-- 70 | |
-- |70-10 |
-- |70-20 |
-- |70-30 |
-- |70-40 |
-- | |70-40-10
-- | |70-40-20
-- | |70-40-30
-- | |70-40-35
-- | |70-40-36
-- |70-50 |
-- | |70-50-10
-- | |70-50-20
-- | |70-50-30
-- | |70-50-40
-- | |70-50-50
-- 95 | |
================================================================================
(5) By Pierre-Yves Delens (PyDelens) on 2021-07-29 11:13:42 in reply to 3 [link] [source]
Hello, Dear, I got some result with this, adapted from SQLite.org docs; a little simpler for a beginning. But the result isn't yet correct (see 'sort order' under SQL code): PageTreeTT1_TreeVw02 : WITH RECURSIVE under_root(ID_Page,level, lbl,slug,OnOff,sort) AS ( SELECT PagesTreeTT1.ID_Page, 0, PagesTreeTT1.PgDescr, PagesTreeTT1.TxtID_Page, PagesTreeTT1.OnOff,PagesTreeTT1.PgSort FROM PagesTreeTT1 WHERE PagesTreeTT1.ParentPage_Id ISNULL AND PagesTreeTT1.OnOff = 1 UNION ALL SELECT PagesTreeTT1.ID_Page, under_root.level+1, PagesTreeTT1.PgDescr, PagesTreeTT1.TxtID_Page, PagesTreeTT1.OnOff,PagesTreeTT1.PgSort FROM PagesTreeTT1 JOIN under_root ON PagesTreeTT1.ParentPage_Id=under_root.ID_Page WHERE PagesTreeTT1.OnOff = 1 ORDER BY 2 DESC ) SELECT (substr('..........',1,level*3) || lbl) AS BranchString, slug, sort FROM under_root; +-------------------------------+------------+------+ | BranchString | slug | sort | +-------------------------------+------------+------+ | Histoire d'une recherche | HistRchch | 10 | | ...Gedinne - et rien d'autre | GDN_ | 20 | | ...Trouver un lieu | TrvLieu | 10 | | ...J'ai trouvé | gTrv | 30 | | Découverte | decouvert | 20 | | ...Sous la Forge - Copinette- | SsLaForge | 30 | | ...Inauguration | inaug | 40 | | Un chantier? | chantier_ | 50 | | Et autour de ce site | autour | 60 | | Infos utiles | infos | 70 | | ...Gedinne (Commune) | GdnCmn | 20 | | ...Vie locale et régionale | VieLocale- | 50 | | ......Socio-économie | SocioEco | 10 | | ......Culturel | culturel | 20 | | ......Nature | nature | 50 | | ......Patrimoine | patrimn | 40 | | ......Politique | politik | 30 | | ...Willerzie (village) | WillVlg | 10 | | ...Commerces | commerces | 30 | | ...Services | services | 40 | | ......Sports - Activités | SportAct | 30 | | ......Hébergements | hebergt | 10 | | ......Restauration | restaur | 20 | | A propos | about | 95 | +-------------------------------+------------+------+ Almost ok but the sort order (example lines 2,3,4) are not following the sort value in this subgroup. The second problem is (see PageTreeTT1_TreeVw02a below): when adding the ParentPage_Id field (alias : parid) in the query, the output BranchString field is buggy for the rows of 1st level (top parents level : "Histoire d'une recherche") ; The BranchString is NULL. PageTreeTT1_TreeVw02a : WITH RECURSIVE under_root(ID_Page,level, lbl,slug, sort, OnOff, parid) AS ( SELECT PagesTreeTT1.ID_Page, 0, PagesTreeTT1.PgDescr, PagesTreeTT1.TxtID_Page, PagesTreeTT1.PgSort, PagesTreeTT1.OnOff, PagesTreeTT1.ParentPage_Id FROM PagesTreeTT1 WHERE PagesTreeTT1.ParentPage_Id ISNULL AND PagesTreeTT1.OnOff = 1 UNION ALL SELECT PagesTreeTT1.ID_Page, under_root.level+1, PagesTreeTT1.PgDescr, PagesTreeTT1.TxtID_Page, PagesTreeTT1.PgSort, PagesTreeTT1.OnOff, PagesTreeTT1.ParentPage_Id FROM PagesTreeTT1 JOIN under_root ON PagesTreeTT1.ParentPage_Id=under_root.ID_Page WHERE PagesTreeTT1.OnOff = 1 ORDER BY 2 DESC ) SELECT (substr('..........',1,level*3) || lbl || ' ' || ID_Page || ' \< ' || parid ) as BranchString, slug, sort FROM under_root; +-----------------------------------------+------------+------+ | BranchString | slug | sort | +-----------------------------------------+------------+------+ | NULL | HistRchch | 10 | | ...Gedinne - et rien d'autre 4 \< 2 | GDN_ | 20 | | ...Trouver un lieu 3 \< 2 | TrvLieu | 10 | | ...J'ai trouvé 5 \< 2 | gTrv | 30 | | NULL | decouvert | 20 | | ...Sous la Forge - Copinette- 10 \< 7 | SsLaForge | 30 | | ...Inauguration 11 \< 7 | inaug | 40 | | NULL | chantier_ | 50 | | NULL | autour | 60 | | NULL | infos | 70 | | ...Gedinne (Commune) 16 \< 14 | GdnCmn | 20 | | ...Vie locale et régionale 19 \< 14 | VieLocale- | 50 | | ......Socio-économie 20 \< 19 | SocioEco | 10 | | ......Culturel 21 \< 19 | culturel | 20 | | ......Nature 24 \< 19 | nature | 50 | | ......Patrimoine 23 \< 19 | patrimn | 40 | | ......Politique 22 \< 19 | politik | 30 | | ...Willerzie (village) 15 \< 14 | WillVlg | 10 | | ...Commerces 17 \< 14 | commerces | 30 | | ...Services 18 \< 14 | services | 40 | | ......Sports - Activités 28 \< 18 | SportAct | 30 | | ......Hébergements 26 \< 18 | hebergt | 10 | | ......Restauration 27 \< 18 | restaur | 20 | | NULL | about | 95 | +-----------------------------------------+------------+------+ This 2d problem could be solved with this endinc SQL string : ... ... ) SELECT ( substr( '..........', 1, level * 3 ) || lbl || ' ' || ID_Page ) AS BranchString, slug, sort , parid FROM under_root; But I 'd like to understand why buggy in a calculated/concatenated field, and not as plain field ('parid'). QUESTION / DEMAND : is there a way to correct this SQL? Or should I switch on Ryan's example (which is a bit too difficult for me for the while)? Thanks on forward