Re: Re: fetching on joined table
Re: Re: fetching on joined table
- Subject: Re: Re: fetching on joined table
- From: email@hidden
- Date: Tue, 12 Apr 2011 09:49:42 +0200 (CEST)
- Message-context: email-message
Hi chuck,
I go to give you more informations about data. I work in IT Universtity in France and we have huge database with lot of table. Here is an example of PDM (5 tables)
person ------------>students--------->degree---------->diploma---------->academic year------>period_param----------------------------->admin_resgistration
(fk_person) (fk_student) (fk_academic_year) (pk an_univ prd_univ) (fields an_univ_prd_univ) (fk_diploma, fk_person, fk_student, fk_academic_year)
and I have lof view (view_student_course on a period ...),
Here is code of view vue_parcours_profil using to have student curse :
CREATE OR REPLACE FORCE VIEW "GEST_UV"."VUE_PROFIL_PARCOURS" ("ETU_ID", "DIPLOME_$C", "REORIENT_$F", "PRD_DEBUT", "PRD_FIN")
AS
SELECT DISTINCT t3.e,
t3.d,
t3.reorient_$f,
MIN(p_deb) over (partition BY t3.e, t3.d, t3.p_fin) debut,
t3.p_fin fin
FROM
(SELECT DISTINCT t1.e,
t1.d,
t1.no,
t1.p p_deb,
NVL(MIN(t2.p) over (partition BY t1.e, t1.d, t1.no), MAX (t1.p) over (partition BY t1.e, t1.d)) p_fin,
CASE
WHEN t1.no = 1
AND t2.r IS NULL
THEN t1.r
ELSE DECODE(t2.r,NULL,'N',t2.r)
END reorient_$f
--DECODE(t2.r,null,'N',t2.r) reorient_$f
FROM
(SELECT DISTINCT etu_id e,
diplome_$c d,
an_univ
prd_univ p,
ROW_NUMBER() OVER (partition BY etu_id,diplome_$c order by an_univ
prd_univ NULLS LAST) no,
DECODE(res_pedag_$c,'RE','O','DR','O','N') r
FROM gerry.etu_inscr_adm eia1
) t1,
(SELECT DISTINCT etu_id e,
diplome_$c d,
an_univ
prd_univ p,
ROW_NUMBER() OVER (partition BY etu_id,diplome_$c order by an_univ
prd_univ NULLS LAST) no,
DECODE(res_pedag_$c,'RE','O','DR','O','N') r
FROM gerry.etu_inscr_adm eia2
) t2
WHERE t1.e = t2.e(+)
AND t1.d = t2.d(+)
AND t1.no < t2.no(+)
AND t1.r <> t2.r(+)
--and t1.r = 'N'
AND ((t1.no = 1
AND NVL(t1.r,'N') IN ('O','N'))
OR (t1.no > 1
AND NVL(t1.r,'N') = 'N'))
) t3;
So when I want all students curse in sql developer this my request :
SELECT vtp.etu_id as STUDENT_ID,
vtp.diplome_$c as DIPLOMA_CODE,
DECODE (vtp.diplome_$c,'ING',d.diplome
' ancien règlement',d.diplome) as DIPLOMA_NAME,
vtp.prd_debut as PERIOD_BEGIN,
vtp.prd_fin as PERIOD_END,
gerry.fonc_trad_prd_lib(vtp.prd_debut,'anprd') as ACADEMIC_YEAR_BEGIN,
gerry.fonc_trad_prd_lib(vtp.prd_fin,'anprd') ACADEMIC_YEAR_END,
vtp.reorient_$f as ORIENTATION,
(SELECT DIPL_SPEC_ABR
' '
DIPL_OPT_ABR
' '
NIVEAU_ADM
FROM gerry.vue_eia_abr veia
WHERE veia.etu_id = vtp.etu_id
AND veia.diplome_$c=vtp.diplome_$c
AND veia.an_univ
veia.prd_univ=vtp.prd_fin
) as DIPLOMA_SPECIFICITY,
(SELECT diplome_num
FROM gest_uv.etu_diplome
WHERE etu_id = vtp.etu_id
AND diplome_$c = vtp.diplome_$c
AND an_univ
prd_univ BETWEEN vtp.prd_debut AND vtp.prd_fin
) as DIPLOMA_NUMBER,
(SELECT SITUATION
FROM gerry.etu_inscr_adm eia,
gerry.ref_situation rs
WHERE rs.situation_$c = eia.situation_$c
AND eia.etu_id = vtp.etu_id
AND eia.diplome_$c =vtp.diplome_$c
AND eia.an_univ
eia.prd_univ=vtp.prd_fin
) as STUDENT_SITUATION,
NVL(
(SELECT DECODE(situation_$c,'DEMI','O','N')
FROM gerry.etu_inscr_adm
WHERE etu_id = vtp.etu_id
AND diplome_$c =vtp.diplome_$c
AND situation_$c='DEMI'
AND an_univ
prd_univ=vtp.prd_fin
),'N') as IS_STUDENT_RESIGNED,
NVL(
(SELECT DECODE(situation_$c,'UTX','O','N')
FROM gerry.etu_inscr_adm
WHERE etu_id = vtp.etu_id
AND diplome_$c =vtp.diplome_$c
AND situation_$c='UTX'
AND an_univ
prd_univ=vtp.prd_fin
),'N') as IS_STUDENT_TRANSFERED
FROM gest_uv.VUE_PROFIL_PARCOURS vtp,
gerry.diplome d
WHERE vtp.diplome_$c = d.diplome_$c
order by prd_debut, prd_fin;
So I must fetch on view vue_profil_parcours, diploma to display all students curse in a WOO table using batch. Here a little example and I have lof of fecthing such as this to do in my apps to display information about, sutdent, teacher so on...
I want a example code How to translate this sql request or what the best practice in WebObjects in this situation? To fast forward in my apps, I create view every time when I want to display this kind of information. This allows me to browse my data in an accurate in WebObjects.
Thanks for your help
Ray,
Message du : 11/04/2011
De : "Chuck Hill " <email@hidden>
A : email@hidden
Copie à : email@hidden
Sujet : Re: fetching on joined table
Hi Chuck,
Tables A, B, C, D haven't relationship but same fileds name.
If they don't have modeled relationships, then you can't use qualifiers.
When i'am using raw rows to translate my sql in webobjects and get my data, I don't have EOF entities but dictionnaries.
So I would like to know what the best practice on my case? create view with my sql request on database and fetching on view in my model?
I think the best practice would be to change the model (and the schema too, if needed) so that there are relationships and you are fetching entities. I very rarely need to do a raw row fetch. If you give us more information on the data, maybe we can suggest a better model.
Chuck
========================================
Message du : 11/04/2011
De : "Chuck Hill " <email@hidden>
A : email@hidden
Copie à : email@hidden
Sujet : Re: fetching on joined table
Hello Ray,
Hi,
I'm newbie on WebObjects and I have big problem to fetching on joined table.
Example :
I have my SQL like that :
A good rule with WebObjects is "If you are thinking about SQL, you are doing it wrong." There are times (i.e. when optimizing) when you do need to think about the SQL, but thinking in terms of objects is usually the better way.
select
a.id b.id as ID,
c.option as option,
decode(d.no, 1, 'one', 2, 'two', 'unknow') as order
WebObjects (EOF) does not do mixed table selects like this (unless you are selecting Raw Rows). It selects whole rows of tables and makes them into related Java objects.
from
ta a, tb b, tc c, td d
where
c.option in ('1', '2','3')
and c.option = b.option
How to translate this SQL request in EOF using qualifier or spec qualifier?
Thanks for your help.
What are the relationships in the model between A, B, C, and D? What are you trying to fetch?
Chuck
--
Chuck Hill Senior Consultant / VP Development
Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems.
--
Chuck Hill Senior Consultant / VP Development
Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems.
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