我在这里被告知
将图像存储在文件系统中,而不是在表格中存储BLOB。
如何将BLOB复制到文件中,并获取其路径(由APEX应用程序访问)?
我想创建一个将BLOB映像保存到文件系统的触发器,并将路径保存到varchar列。
该表具有类似
的结构CREATE TABLE "ALLIMAGES_TBL"
( "ID" NUMBER NOT NULL ENABLE,
"NAME" NVARCHAR2(400),
"FILENAME" VARCHAR2(350 BYTE),
"MIME_TYPE" VARCHAR2(255 BYTE),
"SIZE" NUMBER,
"CHARSET" VARCHAR2(128 BYTE),
"LAST_UPDATE_DATE" DATE,
"BinaryBLOB" BLOB,
"PATH" varchar(260),
答案 0 :(得分:0)
与往常一样,这两个选项都有 pro 和 contra :将图像保存在数据库中,或将它们保存在文件系统中。在我看来,如果只有少数(好的,让我们在大约100秒内测量它们),我宁愿把它们放在一张桌子里。处理它们更容易。因为,一旦他们在文件系统中,你将不得不取得&使用更多(HTML)代码在Apex中显示它们。
无论如何,这是我如何做到的(在以前的Apex版本之一,我相信它是4.0):使用“文件浏览”项目我暂时将图像存储到一个表中(它是WWW_FLOW_FILES;你宁愿使用你的现在拥有自己的表),然后 - 按下按钮触发进程 - 我将它们移动到一个目录中。
流程代码:
declare
-- l_dest_dir is name of the directory (Oracle object) which points
-- to a filesystem directory
l_dest_dir varchar2(30) := pkg_slike.f_dir_slike_upload_dp(:P0_DP);
begin
for cur_r in (select id, filename
from wwv_flow_files
where upper(filename) like 'TS%.JP%G'
)
loop
-- put a picture into L_DEST_DIR
pkg_slike.p_write_blob_to_file(cur_r.id, l_dest_dir);
delete from wwv_flow_files
where id = cur_r.id;
end loop;
end;
程序代码:
PROCEDURE p_write_blob_to_file (p_file_id IN NUMBER, p_dir IN VARCHAR2)
IS
/* 19.04.2012. Taken from Eddie Awad's Blog
http://awads.net/wp/2011/09/20/create-an-application-to-upload-files-using-oracle-apex-in-less-than-10-minutes-video/
*/
l_blob BLOB;
l_blob_length INTEGER;
l_out_file UTL_FILE.file_type;
l_buffer RAW (32767);
l_chunk_size BINARY_INTEGER := 32767;
l_blob_position INTEGER := 1;
l_file_name pkg_general.subt_ime_slike;
BEGIN
-- Retrieve the BLOB for reading
SELECT blob_content, filename
INTO l_blob, l_file_name
FROM wwv_flow_files
WHERE id = p_file_id;
-- Retrieve the SIZE of the BLOB
l_blob_length := DBMS_LOB.getlength (l_blob);
-- Open a handle to the location where you are going to write the BLOB
-- to file.
-- NOTE: The 'wb' parameter means "write in byte mode" and is only
-- available in the UTL_FILE package with Oracle 10g or later
l_out_file :=
UTL_FILE.fopen (p_dir,
l_file_name,
'wb' -- important. If ony w then extra carriage return/line brake
,
l_chunk_size);
-- Write the BLOB to file in chunks
WHILE l_blob_position <= l_blob_length
LOOP
IF l_blob_position + l_chunk_size - 1 > l_blob_length
THEN
l_chunk_size := l_blob_length - l_blob_position + 1;
END IF;
DBMS_LOB.read (l_blob,
l_chunk_size,
l_blob_position,
l_buffer);
UTL_FILE.put_raw (l_out_file, l_buffer, TRUE);
l_blob_position := l_blob_position + l_chunk_size;
END LOOP;
-- Close the file handle
UTL_FILE.fclose (l_out_file);
END p_write_blob_to_file;
希望您能够根据自己的情况调整它。