Oracle dbms_xmldom如何创建blob节点?
我有CR_元素程序,可以添加一个节点。 我现在必须创建一个blob节点,我想知道如何使用像CR_blob_元素这样的过程来创建它 有人能告诉我怎么做吗 问候, 皮埃尔 PS:我正在使用Oracle Database 11g 11.2.0.4.0版Oracle dbms_xmldom如何创建blob节点?,oracle,plsql,blob,xmldom,createtextnode,Oracle,Plsql,Blob,Xmldom,Createtextnode,我有CR_元素程序,可以添加一个节点。 我现在必须创建一个blob节点,我想知道如何使用像CR_blob_元素这样的过程来创建它 有人能告诉我怎么做吗 问候, 皮埃尔 PS:我正在使用Oracle Database 11g 11.2.0.4.0版 CR_BLOB_ELEMENT(l_domdoc in out dbms_xmldom.DOMDocument, ref_node in dbms_xmldom.DOMNode,
CR_BLOB_ELEMENT(l_domdoc in out dbms_xmldom.DOMDocument,
ref_node in dbms_xmldom.DOMNode,
nomel in varchar2,
blobtobeadded in blob)
procedure CR_ELEMENT(l_domdoc in out dbms_xmldom.DOMDocument,
ref_node in dbms_xmldom.DOMNode,
nomel in varchar2,
vnomel in varchar2) as
element dbms_xmldom.DOMElement;
node dbms_xmldom.DOMNode;
text dbms_xmldom.DOMText;
textnode dbms_xmldom.DOMNode;
begin
element := dbms_xmldom.createElement(l_domdoc, nomel);
node := dbms_xmldom.appendChild(ref_node,
dbms_xmldom.makeNode(element));
text := dbms_xmldom.createTextNode(l_domdoc, vnomel);
textnode := dbms_xmldom.appendChild(node, dbms_xmldom.makeNode(text));
end;
如果对某人有用。
请在community.oracle.com上找到odie_63给出的以下答案。
这是完美的工作。
当做
皮埃尔
所以您需要将二进制数据转换为XML文档?如果是这样的话,那么一个选项就是将二进制数据编码为Base64格式。Tks Jokke。我确实将base64编码的blob写入了数据库,但在将其写入xml时,我遇到了麻烦。由于varchar2的限制,它的内容恐怕会被截断。我说的对吗?Base64是基于文本的格式。如果可以将blob转换为clob/varchar2,那么就不会有任何问题。如果大小有限制,只需将数据分割成更小的部分。关于它还有很多其他问题/文章。对不起,我错了,DOM节点大小可能有限制…我已经找到了很多关于这个主题的文章,但实际上我还不清楚。谢谢你抽出时间。
SQL> create table images (
2 id integer
3 , name varchar2(256)
4 , content blob
5 );
Table created
SQL>
SQL> declare
2
3 bf bfile := bfilename('XML_DIR','base64.bin');
4 lob_ptr blob;
5 dest_offs integer := 1;
6 src_offs integer := 1;
7
8 begin
9
10 insert into images (id, name, content)
11 values (1, 'Koala.jpg', empty_blob())
12 returning content into lob_ptr;
13
14 dbms_lob.open(bf, dbms_lob.lob_readonly);
15 dbms_lob.loadblobfromfile(lob_ptr, bf, dbms_lob.getlength(bf), dest_offs, src_offs);
16 dbms_lob.close(bf);
17
18 end;
19 /
PL/SQL procedure successfully completed
SQL> commit;
Commit complete
SQL>
SQL> select id
2 , name
3 , utl_raw.cast_to_varchar2(dbms_lob.substr(content, 30)) as first_bytes
4 , dbms_lob.getlength(content) as lob_size
5 from images
6 /
ID NAME FIRST_BYTES LOB_SIZE
----- ------------ -------------------------------- ----------
1 Koala.jpg /9j/4AAQSkZJRgABAgEAYABgAAD/7g 1068504
SQL>
SQL> declare
2
3 x_doc xmltype;
4 domdoc dbms_xmldom.DOMDocument;
5 domnode dbms_xmldom.DOMNode;
6 domtext dbms_xmldom.DOMText;
7 ostream sys.utl_BinaryOutputStream;
8 chunksize pls_integer;
9 offset pls_integer := 1;
10 buf raw(32767);
11 image blob;
12
13 begin
14
15 select xmlelement("image",
16 xmlelement("id", t.id)
17 , xmlelement("name", t.name)
18 , xmlelement("content")
19 )
20 , t.content
21 into x_doc
22 , image
23 from images t
24 where t.id = 1 ;
25
26 domdoc := dbms_xmldom.newDOMDocument(x_doc);
27
28 -- get /image/content node so that we can append a text node and stream the BLOB to it :
29 domnode := dbms_xslprocessor.selectSingleNode(dbms_xmldom.makeNode(domdoc), '/image/content');
30 domtext := dbms_xmldom.createTextNode(domdoc, null);
31 domnode := dbms_xmldom.appendChild(domnode, dbms_xmldom.makeNode(domtext));
32
33 ostream := DBMS_XMLDOM.setNodeValueAsBinaryStream(domnode);
34 chunksize := dbms_lob.getchunksize(image);
35
36 loop
37 begin
38 -- read BLOB in chunk of <chunksize> :
39 dbms_lob.read(image, chunksize, offset, buf);
40 exception
41 when no_data_found then
42 exit;
43 end;
44 -- write chunk to DOM node :
45 ostream.write(buf, chunksize);
46 offset := offset + chunksize;
47 end loop;
48
49 ostream.flush();
50 ostream.close();
51
52 dbms_xmldom.writeToFile(domdoc, 'XML_DIR/image.xml');
53 dbms_xmldom.freeDocument(domdoc);
54
55 end;
56 /
PL/SQL procedure successfully completed
Output in image.xml :
<image>
<id>1</id>
<name>Koala.jpg</name>
<content>/9j/4AAQSkZJRgABAgEAYABgAAD/7gAOQWRvYmUAZAAAAAAB/+EUI0V4aWYAAE1NACoAAAAIAAcB
MgACAAAAFAAAAGIBOwACAAAABwAAAHZHRgADAAAAAQAEAABHSQADAAAAAQA/AACcnQABAAAADgAA
AADqHAAHAAAH9AAAAACHaQAEAAAAAQAAAH0AAADnMjAwOTowMzoxMiAxMzo0ODoyOABDb3JiaXMA
...
aWpkRY6dqaJY42qFjs8ZZ5nlkjZpmJUiJ1+ijn3dVeTtb4B1R5NJVaEkn/V8+u4Xijpp6SFlimp6
qNHgjlVIgrtLCyxll1NpaT6An6W92mA8HwkyadMeEZJjEDmvE/t/1f5uv//Z</content>
</image>