我是 XPath 新手；我找到了一种方法来做我想做的事，但想知道是否有另一种方法可以在我的代码中节省一些重复。
我有这张桌子：
CREATE TABLE t (
quark_p1 VARCHAR2(4)
, quark_p2 VARCHAR2(7)
, quark_p3 VARCHAR2(6)
, one VARCHAR2(1)
, two VARCHAR2(1)
, three VARCHAR2(1)
, four VARCHAR2(1)
, five VARCHAR2(1)
, six VARCHAR2(1)
, seven VARCHAR2(1)
, eight VARCHAR2(1)
, nine VARCHAR2(1)
)
;
下面的 PL/SQL 匿名块做我想要的，从我给定的 XML 中提取结构到这个表中：
BEGIN
INSERT INTO t (
quark_p1
, quark_p2
, quark_p3
, one
, two
, three
, four
, five
, six
, seven
, eight
, nine
)
SELECT x.quark_p1
, x.quark_p2
, x.quark_p3
, x.one
, x.two
, x.three
, x.four
, x.five
, x.six
, x.seven
, x.eight
, x.nine
FROM XMLTABLE('/BASIS/QUARK'
PASSING XMLTYPE (
'<BASIS>
<QUARK P1="up" P2="charm" P3="bottom">
<NEST>
<ONE>A</ONE>
<TWO>B</TWO>
<THREE>C</THREE>
<FOUR>D</FOUR>
<FIVE>E</FIVE>
<SIX>F</SIX>
<SEVEN>G</SEVEN>
<EIGHT>H</EIGHT>
<NINE>I</NINE>
</NEST>
</QUARK>
<QUARK P1="up" P2="strange" P3="top">
<NEST>
<ONE>J</ONE>
<TWO>K</TWO>
<THREE>L</THREE>
<FOUR>M</FOUR>
<FIVE>N</FIVE>
<SIX>O</SIX>
<SEVEN>P</SEVEN>
<EIGHT>Q</EIGHT>
<NINE>R</NINE>
</NEST>
</QUARK>
</BASIS>')
COLUMNS quark_p1 VARCHAR2(4) PATH '@P1'
, quark_p2 VARCHAR2(7) PATH '@P2'
, quark_p3 VARCHAR2(6) PATH '@P3'
, one VARCHAR2(1) PATH 'NEST/ONE'
, two VARCHAR2(1) PATH 'NEST/TWO'
, three VARCHAR2(1) PATH 'NEST/THREE'
, four VARCHAR2(1) PATH 'NEST/FOUR'
, five VARCHAR2(1) PATH 'NEST/FIVE'
, six VARCHAR2(1) PATH 'NEST/SIX'
, seven VARCHAR2(1) PATH 'NEST/SEVEN'
, eight VARCHAR2(1) PATH 'NEST/EIGHT'
, nine VARCHAR2(1) PATH 'NEST/NINE'
) x;
END;
/
这导致以下结果，这就是我所追求的：
SQL> SELECT * FROM t
2 ;
QUARK_P1 QUARK_P2 QUARK_P3 O T T F F S S E N
-------- -------- -------- - - - - - - - - -
up charm bottom A B C D E F G H I
up strange top J K L M N O P Q R
SQL>
由于“NEST”级别经常重复，我想把它拉到起始节点，仍然得到相同的结果。我正在寻找类似以下的事情：
BEGIN
INSERT INTO t (
quark_p1
, quark_p2
, quark_p3
, one
, two
, three
, four
, five
, six
, seven
, eight
, nine
)
SELECT x.quark_p1
, x.quark_p2
, x.quark_p3
, x.one
, x.two
, x.three
, x.four
, x.five
, x.six
, x.seven
, x.eight
, x.nine
-- Notice, I changed the starting node from /BASIS/QUARK to /BASIS/QUARK/NEST....
FROM XMLTABLE('/BASIS/QUARK/NEST'
PASSING XMLTYPE (
'<BASIS>
<QUARK P1="up" P2="charm" P3="bottom">
<NEST>
<ONE>A</ONE>
<TWO>B</TWO>
<THREE>C</THREE>
<FOUR>D</FOUR>
<FIVE>E</FIVE>
<SIX>F</SIX>
<SEVEN>G</SEVEN>
<EIGHT>H</EIGHT>
<NINE>I</NINE>
</NEST>
</QUARK>
<QUARK P1="up" P2="strange" P3="top">
<NEST>
<ONE>J</ONE>
<TWO>K</TWO>
<THREE>L</THREE>
<FOUR>M</FOUR>
<FIVE>N</FIVE>
<SIX>O</SIX>
<SEVEN>P</SEVEN>
<EIGHT>Q</EIGHT>
<NINE>R</NINE>
</NEST>
</QUARK>
</BASIS>')
-- ...and I changed all the paths here
COLUMNS quark_p1 VARCHAR2(4) PATH '../@P1'
, quark_p2 VARCHAR2(7) PATH '../@P2'
, quark_p3 VARCHAR2(6) PATH '../@P3'
, one VARCHAR2(1) PATH 'ONE'
, two VARCHAR2(1) PATH 'TWO'
, three VARCHAR2(1) PATH 'THREE'
, four VARCHAR2(1) PATH 'FOUR'
, five VARCHAR2(1) PATH 'FIVE'
, six VARCHAR2(1) PATH 'SIX'
, seven VARCHAR2(1) PATH 'SEVEN'
, eight VARCHAR2(1) PATH 'EIGHT'
, nine VARCHAR2(1) PATH 'NINE'
) x;
END;
/
在我看来，它应该可以工作，但我收到了这个错误：
FROM XMLTABLE('/BASIS/QUARK/NEST'
*
ERROR at line 28:
ORA-06550: line 28, column 10:
PL/SQL: ORA-19110: unsupported XQuery expression
ORA-06550: line 2, column 5:
PL/SQL: SQL Statement ignored
SQL>
我错过了一些简单的东西，还是我不能从这里到达那里？
谢谢。