Loading a file into a clob

Question

Given a url pointing to a file hosted on the webserver, is it possible to read the contents of that url into a clob? And if so, how?

Answer 1

Here is a procedure which takes a URL and loads its contents into a table.

The web file is retrieved using UTL_HTTP.GET_PIECES(). This returns an array of strings. If you are working behind a firewall you will need to declare your proxy. Find out more about UTL_HTTP.

The CLOB wrangling uses various bits of DBMS_LOB functionality. The procedure declares a temporary lob variable, appends the pieces of the UTL_HTTP array to it and then finally inserts it into a table. Find out more about DBMS_LOB.

SQL> create or replace procedure pop_file_from_url
  2      (p_url in varchar2)
  3  is
  4      tc clob;
  5      lv_web_page utl_http.html_pieces;
  6  begin
  7
  8      dbms_lob.createtemporary(tc, true);
  9      dbms_lob.open(tc, dbms_lob.lob_readwrite);
 10
 11      lv_web_page := utl_http.request_pieces (p_url);
 12
 13      for i in 1..lv_web_page.count()
 14      loop
 15          dbms_lob.writeappend(tc, length(lv_web_page(i)) ,lv_web_page(i));
 16      end loop;
 17
 18      insert into t23 values (1, tc);
 19
 20      dbms_lob.close(tc);
 21      dbms_lob.freetemporary(tc);
 22
 23  end pop_file_from_url;
 24  /

Procedure created.

SQL> 

If, like me, you are on 11g you will need to add the URL to an Access Control List, otherwise the request will be blocked. Find out more about ACLs.

SQL> exec pop_file_from_url('stackoverflow.com')
BEGIN pop_file_from_url('stackoverflow.com'); END;

*
ERROR at line 1:
ORA-29273: HTTP request failed
ORA-06512: at "SYS.UTL_HTTP", line 1674
ORA-24247: network access denied by access control list (ACL)
ORA-06512: at "APC.POP_FILE_FROM_URL", line 11
ORA-06512: at line 1


SQL> 

After adding the URL for StackOverflow to my ACL I can now insert the file into my table:

SQL> exec pop_file_from_url('stackoverflow.com')

PL/SQL procedure successfully completed.

SQL> select id, dbms_lob.getlength(txt)
  2  from t23
  3  /

        ID DBMS_LOB.GETLENGTH(TXT)
---------- -----------------------
         1                  208226

SQL>