如何在PL / SQL中通过XML进行循环

Question

My XML looks like this :

<root>
  <row>
    <grade>A</grade>
    <Employee>
      <Name>ROBERT SUKIMIN</Name>
      <company>ABC</company>     
    </Employee>
    <Group>117761020</Group>
    <Designation>2014-03-21</Designation>
    <Company_code>5813044</Company_code>
  </row>
  <row>
    <grade>B</grade>
    <Employee>
      <Name>CECIL PAINEM</Name>
      <company>XYZ</company>
    </Employee>
    <Employee>
      <Name>SUGRIWO</Name>
      <company>BCA</company>
    </Employee>
    <Group>40560050</Group>
    <Designation>2012-05-03</Designation>
    <Company_code>0</Company_code>
  </row>
</root>

I would like output:

A Robert Sukimin ABC 117761020 2014-03-21 5813044
B CECIL PAINEM XYZ 405600 2012-05-03 0
B SUGRIWO BCA 405600 2012-05-03 0

How loop in that xml and insert data into oracle table with minimal performance issue, assuming the 1000 record?

Answer 1

You can use multiple XMLTable levels to do this. One XMLTable gets the grade, group, designation etc. and also the current row as XMLType object. The second XMLTable then extracts all of the employee names from that extracted row.

With a CTE just to generate your base XML:

with t (xml) as (
  select xmltype('<root>
  <row>
    <grade>A</grade>
    <Employee>
      <Name>ROBERT SUKIMIN</Name>
      <company>ABC</company>     
    </Employee>
    <Group>117761020</Group>
    <Designation>2014-03-21</Designation>
    <Company_code>5813044</Company_code>
  </row>
  <row>
    <grade>B</grade>
    <Employee>
      <Name>CECIL PAINEM</Name>
      <company>XYZ</company>
    </Employee>
    <Employee>
      <Name>SUGRIWO</Name>
      <company>BCA</company>
    </Employee>
    <Group>40560050</Group>
    <Designation>2012-05-03</Designation>
    <Company_code>0</Company_code>
  </row>
</root>') from dual
)
select x.grade, y.name, y.company, x.group_num, x.designation, x.company_code
from t
cross join xmltable ('/root/row'
  passing t.xml
  columns grade varchar2(1) path 'grade',
    row_xml xmltype path '.',
    group_num number path 'Group',
    designation varchar2(10) path 'Designation',
    company_code number path 'Company_code'
) x
cross join xmltable ('/row/Employee'
  passing x.row_xml
  columns name varchar2(30) path 'Name',
    company varchar2(5) path 'company'
) y;

which gets:

G NAME                           COMPA  GROUP_NUM DESIGNATIO COMPANY_CODE
- ------------------------------ ----- ---------- ---------- ------------
A ROBERT SUKIMIN                 ABC    117761020 2014-03-21      5813044
B CECIL PAINEM                   XYZ     40560050 2012-05-03            0
B SUGRIWO                        BCA     40560050 2012-05-03            0

You can insert the result of that query into another table with insert into some_table (column1, column2, ...) select ... .

In general you don't need PL/SQL to achieve this if the value is coming from a table.

If you have your XML in a PL/SQL variable, eg from your web service call, you can do the same thing using that variable instead of selecting directly from a table. You can still insert directly into your target table. In this example I've assumed your local PL/SQL variable with the web service result is called l_xml and is of type XMLType; and invented the table and column names so you'd obviously use your own real ones:

declare
  l_xml XMLType;
  ...
begin
  -- call web service to populate l_xml
  ...

  insert into you_table(grade, name, company, group_num, designation, company_code)
  select x.grade, y.name, y.company, x.group_num, x.designation, x.company_code
  from xmltable ('/root/row'
    passing l_xml    -- your local XMLType variable
    columns grade varchar2(1) path 'grade',
      row_xml xmltype path '.',
      group_num number path 'Group',
      designation varchar2(10) path 'Designation',
      company_code number path 'Company_code'
  ) x
  cross join xmltable ('/row/Employee'
    passing x.row_xml
    columns name varchar2(30) path 'Name',
      company varchar2(5) path 'company'
  ) y;

  ...
end;

If you're retrieving the web service result into a CLOB you can convert it as part of the call:

  ...
  from xmltable ('/root/row'
    passing XMLType(l_clob)    -- your local CLOB variable
  ...

You don't need to use any loops. You could use a cursor loop over that same query and insert each result into your table one by one, but that would just slow it down for no benefit.