在 Oracle 中使用 XPath 和 XQuery 連接 XML 節點

Question

我有一個 XML 數據存儲在 CLOB 列中，如下所示：

<row id='123456' xml:space='preserve'>
<name>Martin H</name>
<phone>1111</phone>
<phone m='2'>2222</phone>
<phone m='3'></phone>
<sms m='2'>1212</sms>
<sms m='3'>2323</sms>
<email>abc@gmail.com</email>
<email m='3'>xyz@outlook.com</email></row>

如何在 Oracle DB 中使用 Xpath 和 XQuery 以僅在一行中獲得以下預期輸出：

姓名	電話	短信	電子郵件
馬丁 H	1111#2222#	#1212#2323	abc@gmail.com##xyz@outlook.com

基本上，'#' 用於分隔值，並且上述 XML 中任何組的任何缺失標記都將作為空值返回。

任何幫助都感激不盡。 謝謝！

Answer 1

使用XMLTABLE將您的 XML 解析為列，然后您可以在定義路徑時使用string-join運算符來執行與LISTAGG類似的功能。

WITH
    example_table (xml_clob)
    AS
        (SELECT EMPTY_CLOB () || '<row id=''123456'' xml:space=''preserve''>
    <name>Martin H</name>
    <phone>1111</phone>
    <phone m=''2''>2222</phone>
    <phone m=''3''></phone>
    <sms m=''2''>1212</sms>
    <sms m=''3''>2323</sms>
    <email>abc@gmail.com</email>
    <email m=''3''>xyz@outlook.com</email>
</row>' FROM DUAL)
SELECT xt.*
  FROM example_table  et
       CROSS JOIN
       XMLTABLE (
           'row'
           PASSING xmltype (et.xml_clob)
           COLUMNS name VARCHAR2 (100)
                       PATH 'name',
                   phone VARCHAR2 (100)
                       PATH 'string-join(phone,"#")',
                   sms VARCHAR2 (100)
                       PATH 'string-join(sms,"#")',
                   email VARCHAR2 (100)
                       PATH 'string-join(email,"#")') xt;

NAME        PHONE         SMS          EMAIL
___________ _____________ ____________ ________________________________
Martin H    1111#2222#    1212#2323    abc@gmail.com#xyz@outlook.com

更新

在閱讀 kfinity 的評論並更清楚地理解問題后，仍然可以使用XMLTABLE解決問題，然后使用CASE語句將值連接在一起以獲得所需的結果。

WITH
    example_table (xml_clob)
    AS
        (SELECT EMPTY_CLOB () || '<row id=''123456'' xml:space=''preserve''>
    <name>Martin H</name>
    <phone>1111</phone>
    <phone m=''2''>2222</phone>
    <phone m=''3''></phone>
    <sms m=''2''>1212</sms>
    <sms m=''3''>2323</sms>
    <email>abc@gmail.com</email>
    <email m=''3''>xyz@outlook.com</email>
</row>' FROM DUAL)
SELECT xt.name,
          CASE
              WHEN phone1_mtag IS NULL AND phone1 IS NOT NULL THEN phone1
              WHEN phone2_mtag IS NULL AND phone2 IS NOT NULL THEN phone2
              WHEN phone3_mtag IS NULL AND phone3 IS NOT NULL THEN phone3
          END
       || '#'
       || CASE
              WHEN phone1_mtag = '2' AND phone1 IS NOT NULL THEN phone1
              WHEN phone2_mtag = '2' AND phone2 IS NOT NULL THEN phone2
              WHEN phone3_mtag = '2' AND phone3 IS NOT NULL THEN phone3
          END
       || '#'
       || CASE
              WHEN phone1_mtag = '3' AND phone1 IS NOT NULL THEN phone1
              WHEN phone2_mtag = '3' AND phone2 IS NOT NULL THEN phone2
              WHEN phone3_mtag = '3' AND phone3 IS NOT NULL THEN phone3
          END    AS phone,
          CASE
              WHEN sms1_mtag IS NULL AND sms1 IS NOT NULL THEN sms1
              WHEN sms2_mtag IS NULL AND sms2 IS NOT NULL THEN sms2
              WHEN sms3_mtag IS NULL AND sms3 IS NOT NULL THEN sms3
          END
       || '#'
       || CASE
              WHEN sms1_mtag = '2' AND sms1 IS NOT NULL THEN sms1
              WHEN sms2_mtag = '2' AND sms2 IS NOT NULL THEN sms2
              WHEN sms3_mtag = '2' AND sms3 IS NOT NULL THEN sms3
          END
       || '#'
       || CASE
              WHEN sms1_mtag = '3' AND sms1 IS NOT NULL THEN sms1
              WHEN sms2_mtag = '3' AND sms2 IS NOT NULL THEN sms2
              WHEN sms3_mtag = '3' AND sms3 IS NOT NULL THEN sms3
          END    AS sms,
          CASE
              WHEN email1_mtag IS NULL AND email1 IS NOT NULL THEN email1
              WHEN email2_mtag IS NULL AND email2 IS NOT NULL THEN email2
              WHEN email3_mtag IS NULL AND email3 IS NOT NULL THEN email3
          END
       || '#'
       || CASE
              WHEN email1_mtag = '2' AND email1 IS NOT NULL THEN email1
              WHEN email2_mtag = '2' AND email2 IS NOT NULL THEN email2
              WHEN email3_mtag = '2' AND email3 IS NOT NULL THEN email3
          END
       || '#'
       || CASE
              WHEN email1_mtag = '3' AND email1 IS NOT NULL THEN email1
              WHEN email2_mtag = '3' AND email2 IS NOT NULL THEN email2
              WHEN email3_mtag = '3' AND email3 IS NOT NULL THEN email3
          END    AS email
  FROM example_table  et
       CROSS JOIN XMLTABLE ('row'
                            PASSING xmltype (et.xml_clob)
                            COLUMNS name VARCHAR2 (100) PATH 'name',
                                    phone1 VARCHAR2 (100) PATH 'phone[1]',
                                    phone1_mtag VARCHAR2 (100) PATH 'phone[1]/@m',
                                    phone2 VARCHAR2 (100) PATH 'phone[2]',
                                    phone2_mtag VARCHAR2 (100) PATH 'phone[2]/@m',
                                    phone3 VARCHAR2 (100) PATH 'phone[3]',
                                    phone3_mtag VARCHAR2 (100) PATH 'phone[3]/@m',
                                    sms1 VARCHAR2 (100) PATH 'sms[1]',
                                    sms1_mtag VARCHAR2 (100) PATH 'sms[1]/@m',
                                    sms2 VARCHAR2 (100) PATH 'sms[2]',
                                    sms2_mtag VARCHAR2 (100) PATH 'sms[2]/@m',
                                    sms3 VARCHAR2 (100) PATH 'sms[3]',
                                    sms3_mtag VARCHAR2 (100) PATH 'sms[3]/@m',
                                    email1 VARCHAR2 (100) PATH 'email[1]',
                                    email1_mtag VARCHAR2 (100) PATH 'email[1]/@m',
                                    email2 VARCHAR2 (100) PATH 'email[2]',
                                    email2_mtag VARCHAR2 (100) PATH 'email[2]/@m',
                                    email3 VARCHAR2 (100) PATH 'email[3]',
                                    email3_mtag VARCHAR2 (100) PATH 'email[3]/@m') xt;

NAME        PHONE         SMS           EMAIL
___________ _____________ _____________ _________________________________
Martin H    1111#2222#    #1212#2323    abc@gmail.com##xyz@outlook.com