Given a url pointing to a file hosted on the webserver, is it开发者_Python百科 possible to read the contents of that url into a clob? And if so, how?
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>
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