how to give column values as xml element names in Oracle - sql

Question

I have two tables. I am trying to join them and prepare an XML by using SQL/XML (SQLX) in oracle. Here the problem is XMLELEMENT function is taking hardcoded values for element name, but I want to have those names as a column data. Is it possible?
create table PRODUCTEDIT
(
PRODUCTEDIT_NUM NUMBER(12) primary key,
API_NAME VARCHAR2(255)
);
create table PRODUCTEDITPARAMETER
(
PRODUCTEDIT_NUM NUMBER(12) not null,
PARAMETER_SEQ NUMBER(9) not null,
PARAMETER_VALUE VARCHAR2(4000),
CONSTRAINT fk_producteditparameter
FOREIGN KEY (PRODUCTEDIT_NUM )
REFERENCES PRODUCTEDIT(PRODUCTEDIT_NUM )
);
There are 2 records in first table.
PRODUCTEDIT_NUM Api_Name
1 ModifyProd
2 CreateProd
Records in second table:
PRODUCTEDIT_NUM PARAMETER_SEQ PARAMETER_VALUE
1 1 10
1 2 Data
1 3 1
1 4 Data1
1 5 1
2 1 11
2 2 Voice
2 3 1
Now I want to get XMLOUTPUT like below:
<?xml version='1.0'?>
<ModifyProd>
<1>10</1>
<2>Data</2>
<3>1</3>
<4>Data1</4>
<5>1</5>
</ModifyProd>
<CreateProd>
<1>11</1>
<2>Voice</2>
<3>1</3>
</CreateProd>
In above XML we have XMLELEMENT names (ModifyProd,CreateProd, 1,2 e.t.c) coming from table data.I am not able to achieve that by using SQLXML in oracle.
I tried below, but doesn't seem to be working. XMLELEMENT is not taking the value the way I am passing.
SELECT XMLROOT(
XMLELEMENT(d.api_name,
(SELECT XMLAGG(
XMLELEMENT(e.parameter_seq,e.parameter_value
)
)
FROM producteditparameter e
WHERE e.productedit_num = d.productedit_num
)
),version '1.0', standalone yes
)
FROM productedit d

Answer 1

I assume you are looking for this:
WITH t AS
(SELECT 'foo' AS ELEMENT_NAME, 'bar' AS ELEMENT_CONTENT FROM dual)
SELECT XMLELEMENT(EVALNAME ELEMENT_NAME, ELEMENT_CONTENT)
FROM t;
<foo>bar</foo>
Update based on additional input
Your result is not a well-formed XML. A XML document must have only one single root element. So, either you ask for several XML documents, then you can do this:
SELECT
XMLELEMENT(
EVALNAME Api_Name,
XMLAGG(XMLELEMENT(EVALNAME parameter_seq, e.parameter_value) ORDER BY parameter_seq)
) AS xml_result
FROM PRODUCTEDITPARAMETER e
JOIN PRODUCTEDIT d USING (productedit_num)
GROUP BY productedit_num, Api_Name;
<ModifyProd><1>10</1><2>Data</2><3>1</3><4>Data1</4><5>1</5></ModifyProd>
<CreateProd><1>11</1><2>Voice</2><3>1</3></CreateProd>
or if you need a single XML you have to enclose it by another element, e.g.
SELECT
XMLELEMENT("Products",
XMLAGG(
XMLELEMENT(
EVALNAME Api_Name,
XMLAGG(XMLELEMENT(EVALNAME parameter_seq, e.parameter_value) ORDER BY parameter_seq)
)
)
) AS xml_result
FROM PRODUCTEDITPARAMETER e
JOIN PRODUCTEDIT d USING (productedit_num)
GROUP BY productedit_num, Api_Name;
<Products><ModifyProd><1>10</1><2>Data</2><3>1</3><4>Data1</4><5>1</5></ModifyProd><CreateProd><1>11</1><2>Voice</2><3>1</3></CreateProd></Products>

Answer 2

Another solution if I understood what you want:
WITH t AS
( SELECT LEVEL col1, 'test' || LEVEL col2
FROM DUAL
CONNECT BY LEVEL < 10)
SELECT XMLSERIALIZE (DOCUMENT (xmltype (CURSOR (SELECT col1, col2 FROM t))) INDENT SIZE = 0)
FROM DUAL;
Then, you can use a XSD to transform the output as you want.
Hope it helps