使用Oracle 11g的XMLtable [英] XMLtable with Oracle 11g
问题描述
这是一个示例表:
create table xmltemp (mydoc xmltype)
这是一个小的xml文档:
Here is a small xml doc for it:
insert into xmltemp values (
xmltype
('<?xml version="1.0"?>
<countries>
<country>
<name>Canada</name>
</country>
<country>
<name>US</name>
<states>
<state>
<name>Washington</name>
<name>Oregon</name>
</state>
</states>
</country>
</countries>
')
)
请注意,加拿大没有州"元素,而美国则具有. 我正在尝试获取这些查询结果(顺序和格式并不重要):
Notice that Canada does not have a 'states' element but the US does. I'm trying to get these query results (order and formatting is not important):
Canada,
US,Washington
US,Oregon
执行此操作时,结果中同时看到加拿大和美国:
When I execute this, I see both Canada and the US in the result:
select
countryname
from xmltemp,
xmltable('/countries/country' passing mydoc
columns countryname varchar2(10) path 'name')
执行此操作时,会同时获得两种状态:
When I do this, I get both the states:
select
statename
from xmltemp,
xmltable('/countries/country/states/state/name' passing mydoc
columns statename varchar2(20) path '.') c
我尝试这样做是为了获取国家和州,但是oracle似乎不喜欢'..'语法:
I tried this to get both country and states, but it seems oracle does not like the '..' syntax:
select
statename
from xmltemp,
xmltable('/countries/country/states/state/name' passing mydoc
columns statename varchar2(20) path '.',
countryname varchar2(20) path '../../../name') c
出现错误:
ORA-19110: unsupported XQuery expression
尝试这种方法时,由于两种状态,我会收到多项目"错误:
When I try this, I get the 'multi-item' error because of the two states:
select
countryname,
statename
from xmltemp,
xmltable('/countries/country' passing mydoc
columns countryname varchar2(10) path 'name',
statename varchar2(20) path 'states/state/name') c
这是错误:
ORA-19279: XPTY0004 - XQuery dynamic type mismatch: expected singleton
sequence - got multi-item sequence
什么是查询,它将使我获得所需的输出:
What's a query that will get me my desired output of:
Canada,
US,Washington
US,Oregon
谢谢
推荐答案
尝试一下:
select X.COUNTRYNAME, Y.STATENAME
from XMLTEMP
,xmltable('/countries/country'
passing MYDOC
columns COUNTRYNAME varchar2(20) path './name',
STATES xmltype path './states') X,
xmltable('/states/state/name' passing X.STATES
columns STATENAME varchar2(20) path '.') (+) Y
因为您有多个状态,所以您应该加入另一个xml表.由于一些国家没有州,因此它需要成为左派外部联合.我使用的是(+)
的旧方法,因为我在10g上尝试使用它,在10g中使用left outer join
似乎存在问题,但显然在11g
中应该没问题.
Because you have multiple states you should join to another xml table. As some countries have no states then it needs to be a left outer join. I'm using the old method of (+)
as I'm trying this on 10g and it seems there's a problem using left outer join
in 10g but apparently it should be fine in 11g
.
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