sqlplus下加载CLOB 字段的乱码问题

tom 在 expert one on one 中提到了 LOB 类型加载到数据库的方法

tom大师的结果当然不能怀疑。于是我在生产上用sqlplus 做了这个实际操作。之前都用dev来更新。

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

--这里发现的确是加载了数据进去。但是数据查询出来为乱码。

--难道是tom的方法有误？查询了mos 发现 文档ID 562717.1，说明了这个问题，继续看解决办法ID 437432.1

--问题的出现是存储过程dbms_lob.loadfromfile 存在bug,加载file的时候 因为bfile为二进制类型,对于二进制类型

--加载的转换该存储过程不能正确分辨。

--问题的解决：使用 loadclobfromfile/loadblobfromfile 过程来替代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

--结果正常。

--保存下mos 的解决办法

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;
/