SQL XML XML 트리 만들기 (부모 자식)의 명시 적 문제
-
21-12-2019 - |
문제
SQL 쿼리에 지정된 관계에 따라 XML을 출력하지 않는 SQL Server에서 XML을 명시 적으로 직면 해 있습니다.쿼리는 Pubs 데이터베이스에서 수행되며 XML 경로는 XML 명시 적으로 Trainer가 필요로하는 것이 더 쉽습니다.
SELECT 1 AS Tag,
NULL AS Parent,
NULL AS [TitleTypes!1],
NULL AS [TitleType!2!Type],
NULL AS [TitleType!2!AveragePrice],
NULL AS [Title!3!title_id],
NULL AS [Title!3!price]
UNION ALL
SELECT 2,
1,
NULL ,
type AS [TitleType!2!Type],
AVG(price) AS [TitleType!2!AveragePrice],
NULL AS [Title!3!title_id],
NULL AS [Title!3!price]
from titles
GROUP BY type
UNION ALL
SELECT 3,
2,
NULL ,
type AS [TitleType!2!Type],
NULL AS [TitleType!2!AveragePrice],
title_id AS [Title!3!title_id],
price AS [Title!3!price]
from titles
FOR XML EXPLICIT;
.
생성 된 출력 :
<TitleTypes>
<TitleType Type="business " AveragePrice="13.7300" />
<TitleType Type="mod_cook " AveragePrice="11.4900" />
<TitleType Type="popular_comp" AveragePrice="21.4750" />
<TitleType Type="psychology " AveragePrice="13.5040" />
<TitleType Type="trad_cook " AveragePrice="15.9633" />
<TitleType Type="UNDECIDED ">
<Title title_id="BU1032" price="19.9900" />
<Title title_id="BU1111" price="11.9500" />
<Title title_id="BU2075" price="2.9900" />
<Title title_id="BU7832" price="19.9900" />
<Title title_id="MC2222" price="19.9900" />
<Title title_id="MC3021" price="2.9900" />
<Title title_id="MC3026" />
<Title title_id="PC1035" price="22.9500" />
<Title title_id="PC8888" price="20.0000" />
<Title title_id="PC9999" />
<Title title_id="PS1372" price="21.5900" />
<Title title_id="PS2091" price="10.9500" />
<Title title_id="PS2106" price="7.0000" />
<Title title_id="PS3333" price="19.9900" />
<Title title_id="PS7777" price="7.9900" />
<Title title_id="TC3218" price="20.9500" />
<Title title_id="TC4203" price="11.9500" />
<Title title_id="TC7777" price="14.9900" />
</TitleType>
</TitleTypes>
.
원하는 출력 :
<TitleTypes>
<TitleType Type="business" AveragePrice="11.22">
<Title title_id="BU1111" Price="11.34"/>
<Title title_id="TC7777" Price="14.2"/>
</TitleType>
<TitleType Type="popular_comp" AveragePrice="13.99">
<Title title_id="BU1111" Price="15.9"/>
<Title title_id="TC7777" Price="16.22"/>
</TitleType>
</TitleTypes>
. 해결책
일반적으로 명시적인 모드가 전혀 필요하지 않습니다.거의 모든 XML을 생성 할 수 있습니다 XML 경로의 경우 :
select
t1.type as [@Type],
avg(t1.price) as [@AveragePrice],
(
select
t2.title_id as [@title_id],
t2.price as [@price]
from titles as t2
where t2.type = t1.type
for xml path('Title'), type
)
from titles as t1
group by t1.type
for xml path('TitleType'), root('TitleTypes')
.
select
t1.type as [Type],
avg(t1.price) as AveragePrice,
(
select
t2.title_id
t2.price
from titles as t2
where t2.type = t1.type
for xml raw('Title'), type
)
from titles as t1
group by t1.type
for xml raw('TitleType')
.
다른 팁
여기에 저에게 일한 해결책이 있습니다.주문 BY 절을보십시오.SQL Server Management Studio를 사용중인 경우 BY 절에서는 원하는대로 출력 XML을 포맷 할 수있는 열 이름을 볼 수 있습니다.
SELECT 1 AS Tag,
NULL AS Parent,
NULL AS [TitleTypes!1],
NULL AS [TitleType!2!Type],
NULL AS [TitleType!2!AveragePrice],
NULL AS [Title!3!title_id],
NULL AS [Title!3!price]
UNION ALL
SELECT 2,
1,
NULL ,
type AS [TitleType!2!Type],
AVG(price) AS [TitleType!2!AveragePrice],
NULL AS [Title!3!title_id],
NULL AS [Title!3!price]
from titles
GROUP BY type
UNION ALL
SELECT 3,
2,
NULL ,
type AS [TitleType!2!Type],
NULL AS [TitleType!2!AveragePrice],
title_id AS [Title!3!title_id],
price AS [Title!3!price]
from titles
ORDER BY [TitleTypes!1], [TitleType!2!Type], [Title!3!title_id] ,Tag
FOR XML EXPLICIT;
.
p.s.XML 명시 적 짜증이납니다.그러나 실제로 실제로 오래된 시스템을 개발 / 업그레이드하는 경우 새로운 기술로 대체하기 전에 알아야합니다.
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