sqlplus下加載CLOB 字段的亂碼問題

tom 在 expert one on one 中提到了 LOB 類型加載到數據庫的方法

tom大師的結果當然不能懷疑。於是我在生產上用sqlplus 做了這個實際操作。之前都用dev來更新。

select dbms_lob.getlength(introabr) from Dbwebins.Tb_Rationtype where c_rationtype=100009;
--46204
declare
a_clob clob;
bfile_name bfile :=bfilename('BUS_DMP','1.txt');
begin
  update Dbwebins.Tb_Rationtype set introabr=empty_clob() where c_rationtype=100009
  returning introabr into a_clob;
  dbms_lob.fileopen(bfile_name);
  dbms_lob.loadfromfile(a_clob,bfile_name,dbms_lob.getlength(bfile_name));
  dbms_lob.fileclose(bfile_name);
  commit;
end;
select dbms_lob.getlength(introabr) from Dbwebins.Tb_Rationtype where c_rationtype=100009;
--84942

--這裏發現的確是加載了數據進去。但是數據查詢出來爲亂碼。
--難道是tom的方法有誤？查詢了mos 發現 文檔ID 562717.1，說明了這個問題，繼續看解決辦法ID 437432.1
--問題的出現是存儲過程dbms_lob.loadfromfile 存在bug,加載file的時候 因爲bfile爲二進制類型,對於二進制類型
--加載的轉換該存儲過程不能正確分辨。
--問題的解決：使用 loadclobfromfile/loadblobfromfile 過程來替代loadfromfile。

SQL>  CREATE TABLE test_clob (id NUMBER, col_clob CLOB);
Table created.
SQL> INSERT INTO test_clob VALUES(1, EMPTY_CLOB());
1 row created.
SQL> commit;
Commit complete.

 

SQL> CREATE OR REPLACE PROCEDURE file_to_clob IS   
  2   b_fil bfile := BFILENAME('FILE_DUMP', '&filename'); 
  3   -- Ensure f.txt exists   
 v_clob CLOB;   
 dest_offset NUMBER := 1;  
 source_offset NUMBER := 1;   
  7   src_csid NUMBER := NLS_CHARSET_ID('ZHS16GBK');  
 lang_ctx INTEGER := DBMS_LOB.DEFAULT_LANG_CTX;   
  9   warn INTEGER; 
 BEGIN   
 11   -- Retrieve the lob locator   
 SELECT col_clob INTO v_clob FROM test_clob WHERE id = 1 FOR UPDATE;    
 13   -- Open the target CLOB and the source BFILE   
 DBMS_LOB.OPEN(v_clob, DBMS_LOB.LOB_READWRITE);   
 DBMS_LOB.OPEN(b_fil, DBMS_LOB.FILE_READONLY);  
 16   -- Load the contents of the bfile into the CLOB column  
 DBMS_LOB.LOADCLOBFROMFILE(v_clob, b_fil, DBMS_LOB.LOBMAXSIZE, dest_offset, source_offset,src_csid,lang_ctx, warn); 
 18   -- Check for the warning   
 IF warn = DBMS_LOB.WARN_INCONVERTIBLE_CHAR THEN     
 DBMS_OUTPUT.PUT_LINE('Some Characters couldn''t be converted');   
 -- Close the LOBs   
 END IF;     
 22   -- Close the LOBs   
 23   DBMS_LOB.CLOSE(v_clob);   
 24   DBMS_LOB.CLOSE(b_fil); 
 END; 
 26   /
Enter value for filename: 1.txt
old   2:  b_fil bfile := BFILENAME('FILE_DUMP', '&filename');
new   2:  b_fil bfile := BFILENAME('FILE_DUMP', '1.txt');
Procedure created.

SQL> set heading off
SQL> set line 1000
SQL> set long 50000
SQL> select * from test_clob;

         1 --------------------------------------------------------------------------------

           --
           -- File name:   latchprof.sql ( Latch Holder Profiler )
           -- Purpose:     Perform high-frequency sampling on V$LATCHHOLDER
           --              and present a profile of latches held by sessions
           --
           -- Author:      Tanel Poder
           -- Copyright:   (c) http://www.tanelpoder.com
           --
           -- Usage:       @latchprof <what> <sid> <latch name> <#samples>
           --              @latchprof name 350 % 100000                - monitor all
           latches SID 350 is holding

           --              @latchprof sid,name % library 1000000       - monitor which
           SIDs hold latches with "library" in their name
           --              @latchprof sid,name,laddr % 40D993A0 100000 - monitor which
           SIDs hold child latch with address 0x40D993A0
           -- Other:
           --              The sampling relies on NESTED LOOP join method and having
           --              V$LATCHHOLDER as the inner (probed) table. Note that on 9i
           --              you may need to run this script as SYS as it looks like
           otherwise
           --              the global USE_NL hint is not propagated down to X$ base
           tables
           --
           --              The join in exec plan step 8 MUST be a NESTED LOOPS join, this

           is how
           --              the high speed sampling of changing dataset from V$LATCHHOLDE

--結果正常。

--保存下mos 的解決辦法

 CREATE TABLE test_clob (id NUMBER, col_clob CLOB);
 INSERT INTO test_clob VALUES(1, EMPTY_CLOB());
 
 CREATE OR REPLACE PROCEDURE file_to_clob IS   
 b_fil bfile := BFILENAME('FILE_DUMP', '&filename'); 
 -- Ensure f.txt exists   
 v_clob CLOB;   
 dest_offset NUMBER := 1;  
 source_offset NUMBER := 1;   
 src_csid NUMBER := NLS_CHARSET_ID('ZHS16GBK');  
 lang_ctx INTEGER := DBMS_LOB.DEFAULT_LANG_CTX;   
 warn INTEGER; 
 BEGIN   
 -- Retrieve the lob locator   
 SELECT col_clob INTO v_clob FROM test_clob WHERE id = 1 FOR UPDATE;    
 -- Open the target CLOB and the source BFILE   
 DBMS_LOB.OPEN(v_clob, DBMS_LOB.LOB_READWRITE);   
 DBMS_LOB.OPEN(b_fil, DBMS_LOB.FILE_READONLY);  
 -- Load the contents of the bfile into the CLOB column  
 DBMS_LOB.LOADCLOBFROMFILE(v_clob, b_fil, DBMS_LOB.LOBMAXSIZE, dest_offset, source_offset,src_csid,lang_ctx, warn); 
 -- Check for the warning   
 IF warn = DBMS_LOB.WARN_INCONVERTIBLE_CHAR THEN     
 DBMS_OUTPUT.PUT_LINE('Some Characters couldn''t be converted');   
 END IF;     
 -- Close the LOBs   
 DBMS_LOB.CLOSE(v_clob);   
 DBMS_LOB.CLOSE(b_fil); 
 END; 
 /