【SQL】Oracle BLOB 批量導入導出圖片到文件夾相關語句

本文主要介紹 Oracle下 批量導入導出圖片的方法，存儲過程

Oracle LOB 類型介紹

BLOB的含義

BLOB (binary large object)，二進制大對象，是一個可以存儲二進制文件的容器。 主要圖片、聲音文件等,保存位圖

CLOB的含義

CLOB(Character Large Object),它與LONG數(shù)據(jù)類型類似，只不過CLOB用于存儲數(shù)據(jù)庫中的大型單字節(jié)字符數(shù)據(jù)塊，不支持寬度不等的字符集。可存儲的最大大小為4G字節(jié)

.CLOB使用CHAR來保存數(shù)據(jù)。 如：保存XML文檔。

批量導入導出

批量導入

--創(chuàng)建表，及目錄
create table image_lob(t_id varchar2(10) not null,name varchar2(30),t_image blob not null);
create or replace directory "images_dump" as '/home/oracle/images_dump/';
--創(chuàng)建存儲過程
create or replace procedure img_insert(tid varchar2,vname varchar2,filename varchar2) as
f_lob bfile;
b_lob blob;
begin 
insert into image_lob(t_id,name,t_image) values(tid,vname,empty_blob()) return t_image into b_lob;
f_lob:=bfilename('images_dump',filename);
dbms_lob.fileopen(f_lob,dbms_lob.file_readonly);
dbms_lob.loadfromfile(b_lob,f_lob,dbms_lob.getlength(f_lob));
dbms_lob.fileclose(f_lob);
commit;
end;
/
--執(zhí)行導入
exec img_insert(89898989,'firsouler','dbwn.png');
exec img_insert(16211779,'abc','adr.png');

批量導出

--創(chuàng)建導出目錄,注意權限
create or replace directory BLOBDIR as '/home/oracle/images_exp'; 
grant read,write on directory BLOBDIR to mytest;
--創(chuàng)建過程,本例使用t_id,name列作為照片名字,根據(jù)t_id 排序獲取rownum
CREATE OR REPLACE PROCEDURE GET_PIC_BLOB(i_xh VARCHAR2) IS
l_file UTL_FILE.FILE_TYPE;
l_buffer RAW(32767);
l_amount BINARY_INTEGER := 32767;
l_pos INTEGER := 1;
l_name VARCHAR2(30);
l_id VARCHAR2(30);
l_blob BLOB;
l_blob_len INTEGER;
BEGIN
with tmp_image as (select rownum as rn,t_id,name,t_image from image_lob order by t_id) 
select t_id,name,t_image into l_id,l_name,l_blob  from tmp_image where rn = i_xh;
l_blob_len := DBMS_LOB.GETLENGTH(l_blob);
l_file := UTL_FILE.FOPEN('BLOBDIR', l_id || '_' || l_name || '.jpg', 'WB', 32767);
WHILE l_pos < l_blob_len LOOP
DBMS_LOB.READ(l_blob, l_amount, l_pos, l_buffer);
UTL_FILE.PUT_RAW(l_file, l_buffer, TRUE);
l_pos := l_pos + l_amount;
END LOOP;
UTL_FILE.FCLOSE(l_file);
EXCEPTION
WHEN OTHERS THEN
dbms_output.put_line(SQLERRM); 
IF UTL_FILE.IS_OPEN(l_file) THEN
UTL_FILE.FCLOSE(l_file);
END IF;
RAISE;
END GET_PIC_BLOB;
/
--循環(huán)導出200個圖片,以列t_id排序獲取rownum
declare
cursor cur is
with  t as (select rownum as rn from image_lob order by t_id) select rn from t  where rownum <= 200; --導出前200張
begin
for rec in cur loop
GET_PIC_BLOB(rec.rn);
end loop;
end;
/