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NLS and The Case of the Missing Kanji Brian Hitchcock OCP DBA 8, 8i, 9i Global Sales IT Sun Microsystems NoCOUG.

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Presentation on theme: "NLS and The Case of the Missing Kanji Brian Hitchcock OCP DBA 8, 8i, 9i Global Sales IT Sun Microsystems NoCOUG."— Presentation transcript:

1 NLS and The Case of the Missing Kanji Brian Hitchcock OCP DBA 8, 8i, 9i Global Sales IT Sun Microsystems brian.hitchcock@sun.com brhora@aol.com NoCOUG NLS -- National Language Support Kanji -- Japanese characters Brian Hitchcock November 13, 2003Page 1 www.brianhitchcock.net

2 Brian Hitchcock November 13, 2003Page 2 NoCOUG www.brianhitchcock.net How It All Started  Existing Sybase database and application  Needed to convert to Oracle  Use Oracle Migration Workbench – OMWB works well  I wasn’t told there was multi-byte data in the Sybase database  After the migration to Oracle – Kanji data were missing

3 Brian Hitchcock November 13, 2003Page 3 NoCOUG www.brianhitchcock.net Kanji Become Lost  How was Kanji stored in Sybase?  How was application working with Sybase?  Why lost when migrated to Oracle?  How to fix in Oracle?  Would application work with Oracle?

4 Brian Hitchcock November 13, 2003Page 4 NoCOUG www.brianhitchcock.net Before Upgrade to Oracle Source System EUC-JP character encoding Application Sybase Db character set ISO1 Netscape Browser EUC-JP character code for this character is 0xB0A1 0xB0A1 Source system inserts bytes of Kanji characters into db Browser examines each byte, detects multi-byte characters, displays Kanji character Select “Japanese (Auto-Detect)” character set in Netscape to view Kanji characters Application retrieves char data generates HTML

5 Brian Hitchcock November 13, 2003Page 5 NoCOUG www.brianhitchcock.net Moving Sybase Data to Oracle Flat file produced using Sybase bcp utility Existing Sybase Db character set ISO1 Netscape Browser EUC-JP character code for this character is 0xB0A1 0xB0A1 0x3021 Character set WE8ISO8859P1 Browser displays the characters for byte codes 0x30 and 0x21 which are 0 and ! 0! SQL*Loader Oracle defaults to US7ASCII 0xB0A1 0x3021 Oracle Db 0xB0A1 Application retrieves char data generates HTML

6 Brian Hitchcock November 13, 2003Page 6 NoCOUG www.brianhitchcock.net Moving Sybase Data to Oracle  What happened? – SQL*Loader defaults to US7ASCII character set  7-bits per character – SQL*Loader stripped the 8th bit off each byte  8th bit set to 0 – 8-bit characters are now 7-bit characters – Original character data is lost – 8-bit characters can’t be represented in the US7ASCII character set

7 Brian Hitchcock November 13, 2003Page 7 NoCOUG www.brianhitchcock.net US7ASCII to WE8ISO8859P1 B0A1 hexadecimal B 0 A 1 1011 0000 1010 0001 strip off 8th (highest order) bit, set this bit to 0 0011 0000 0010 0001 3 0 2 1 0! EUC-JP character code for this character is 0xB0A1 Browser reads each byte, sees the 8th bit set to 0, decides that each byte represents a single byte character, character codes 30 and 21 represent the characters 0 and ! Hex Decimal Binary A 10 1010 B 11 1011 C 12 1100 D 13 1101 E 14 1110 F 15 1111

8 Brian Hitchcock November 13, 2003Page 8 NoCOUG www.brianhitchcock.net Fix -- Sybase Data to Oracle Flat file produced using Sybase bcp utility Existing Sybase Db character set ISO1 Netscape Browser EUC-JP character code for this character is 0xB0A1 0xB0A1 Character set WE8ISO8859P1 Browser detects multi-byte characters, displays Kanji character SQL*Loader NLS_LANG=WE8ISO8859P1 0xB0A1 Oracle Db 0xB0A1 Application retrieves char data generates HTML Note: WE8ISO8859P1 character set does not support Kanji characters

9 Brian Hitchcock November 13, 2003Page 9 NoCOUG www.brianhitchcock.net Current Oracle Production Source System EUC-JP character encoding Application Oracle Db character set WE8ISO8859P1 Netscape Browser EUC-JP character code for this character is 0xB0A1 0xB0A1 Source system inserts bytes of Kanji characters into db Browser examines each byte, detects multi-byte characters, displays Kanji character Select “Japanese (Auto-Detect)” character set in Netscape to view Kanji characters Application retrieves char data generates HTML Note: WE8ISO8859P1 character set does not support Kanji characters

10 Brian Hitchcock November 13, 2003Page 10 NoCOUG www.brianhitchcock.net Existing Application  How does it store/retrieve Kanji? – Multi-byte Kanji characters – Stored in WE8ISO8859P1 (single-byte) db – Application  JDBC retrieves bytes from WE Oracle db  Java generates HTML, sent to client browser  Netscape, view HTML using “Japanese (Auto- Detect)” character set  Display Kanji

11 Brian Hitchcock November 13, 2003Page 11 NoCOUG www.brianhitchcock.net Existing Application Netscape Browser Character set WE8ISO8859P1 Oracle Db Application Retrieves character data Generate HTML Send HTML to client browser Browser detects multi-byte characters, displays Kanji character ISO1 Converts 8859-1 to UCS2 UCS2 ISO18859-1 Japanese Auto-Detect 8859-1 UCS2 -- 2 byte Unicode

12 Brian Hitchcock November 13, 2003Page 12 NoCOUG www.brianhitchcock.net Existing Application  Each piece of software makes some decision (default) about character set  You need to understand this process for your application

13 Brian Hitchcock November 13, 2003Page 13 NoCOUG www.brianhitchcock.net What Really Happened?  Source Kanji data – From EUC-JP character set – Multi-byte  Kanji multi-byte stored in Sybase db – Default character set ISO-1  8-bit, single-byte  Kanji multi-byte stored in Oracle db – Character set WE8ISO8859P1  8-bit, single-byte

14 Brian Hitchcock November 13, 2003Page 14 NoCOUG www.brianhitchcock.net Convert to UTF8  Why? – Eliminate all the issues shown so far – Store multiple languages correctly  Correctly encoded – Support clients inserting data in languages other than Japanese Kanji – Existing application can only support languages based on Latin characters and Kanji

15 Brian Hitchcock November 13, 2003Page 15 NoCOUG www.brianhitchcock.net Conversion is Simple -- Isn’t It?  Export WE8ISO8859P1 database – Set export client NLS_LANG – AMERICAN_AMERICA.WE8ISO8859P1  Import into UTF8 database – Set import client NLS_LANG – AMERICAN_AMERICA.WE8ISO8859P1  Test application – Application works! – Is everything OK?

16 Brian Hitchcock November 13, 2003Page 16 NoCOUG www.brianhitchcock.net Meanwhile, Back at the Ranch  While application testing is going on – Insert sample bytes for Kanji into WE db  Use Oracle SQL CHR() function – Export from WE db, import into UTF8 db – Examine same bytes in UTF8 db – Compare UTF8 bytes to manually generated UTF8 bytes for the Kanji characters – NOT the same bytes!  What does this mean?

17 Brian Hitchcock November 13, 2003Page 17 NoCOUG www.brianhitchcock.net UTF8 Encoding Process  Think your life is boring? JA16EUC to UTF8 Conversion JA16EUC encoding is 0xB0A1, Unicode code point for this character is 4E9C (no formula for this, Oracle uses a lookup table) Number of bytes used in UTF8 encoding based on Unicode code point: Unicode UTF8 bytes 0x0000 - 0x007f 0xxxxxxx 0x0080 - 0x07ff 110xxxxx 10xxxxxx 0x0800 - 0xffff 1110xxxx 10xxxxxx 10xxxxxx 4E9C requires 3 bytes in UTF8 4E9C bit pattern is 0100 1110 1001 1100 right-most 6 bits go to third UTF8 byte 01 1100 next 6 bits go to second UTF8 byte 1110 10 remaining 4 bits go in first UTF8 byte 0100 11100100 10111010 10011100 E 4 B A 9 C UTF8 character code is 0xE4BA9C Metalink Doc ID: Note:69518.1 Determining the codepoint for UTF8 characters

18 Brian Hitchcock November 13, 2003Page 18 NoCOUG www.brianhitchcock.net Bytes is Bytes Unicode UCS2 UTF8 ISO-2022-JP JIS EUC-JP Shift-JIS UTF8 byte code for this character is 0xE4BA9C Kanji character encodings shown for the various character sets Unicode byte code for this character is 0x4E9C ISO-2022-JP character code for this character is 0x3021 JIS row/cell values for this character are Row 16, Column 1 EUC-JP byte code for this character is 0xB0A1 Shift-JIS byte code for this character is 0x889F Formula Unicode lookup table

19 Brian Hitchcock November 13, 2003Page 19 NoCOUG www.brianhitchcock.net Conversion Issue Application Oracle Db character set WE8ISO8859P1 Export File Import loads export file character set WE8ISO8859P1 Oracle Db Character set UTF8 Netscape Browser View file 0xB0A1 0xC2B0, 0xC2A1 EUC-JP character code for this character is 0xB0A1 Oracle export hard codes the source db character set into the export file Flat file Select char data Spool to file Browser displays the characters for character codes 0xC2B0, 0xC2A1 which are the degree sign and the inverted exclamation mark °¡ Correct UTF8 byte code for this character is 0xE4BA9C

20 Brian Hitchcock November 13, 2003Page 20 NoCOUG www.brianhitchcock.net Import to UTF8 Conversion Existing WE8ISO8859P1 data to UTF8 Conversion EUC-JP encoding for the character is 0xB0A1, but import detects that the data came from a single-byte export file (WE8ISO8859P1) Import reads each byte, one at a time, 0xB0A1 becomes 0xB0 followed by 0xA1, and converts these to the Unicode (UCS2) equivalent -- for single-byte character codes, the Unicode equivalent simply has two leading bytes of 0's -- 0xB0 and 0xA1 become U+00B0 and U+00A1, import then converts from UCS2 to UTF8 Number of bytes used in UTF8 encoding based on Unicode code point: Unicode UTF8 bytes 0x0000 - 0x007f 0xxxxxxx 0x0080 - 0x07ff 110xxxxx 10xxxxxx 0x0800 - 0xffff 1110xxxx 10xxxxxx 10xxxxxx 00B0 and 00A1 both require 2 bytes in UTF8 00B0 bit pattern is 00A1 bit pattern is 0000 0000 1011 0000 0000 0000 1010 0001 right-most 6 bits go to second UTF8 byte next 5 bits go in first UTF8 byte 1100 0010 1011 0000 1100 0010 1010 0001 C 2 B 0 C 2 A 1 WE8ISO8859P1 character code 0xB0A1 becomes UTF character codes 0xC2B0, 0xC2A1 The correct conversion of this EUC-JP character code 0xB0A1 to UTF8 is 0xE4BA9C

21 Brian Hitchcock November 13, 2003Page 21 NoCOUG www.brianhitchcock.net What Happened?  Oracle did exactly what is was told to do – Take bytes from WE database – Convert to UTF8 bytes – Export file was made from WE database – WE is single-byte character set – Convert each byte one at a time to UTF8 – Kanji character consists of 2 bytes in WE db – Converting each byte to UTF8 not the same as converting the pair of bytes to UTF8  Yeah, but, application works! (?)

22 Brian Hitchcock November 13, 2003Page 22 NoCOUG www.brianhitchcock.net Where’s the Problem?  UTF8 db has Kanji as 0xC2B0, 0xC2A1  Correct UTF8 encoding is 0xE4BA9C  If new, correctly encoded Kanji is inserted – Database contains two sets of bytes for same Kanji character – How does app deal with this?  Existing app only works using Netscape Japanese (Auto-Detect) character set – App is not really UTF8, only works for Japanese characters

23 Brian Hitchcock November 13, 2003Page 23 NoCOUG www.brianhitchcock.net How Does Application Work?  Review – Oracle db created using UTF8 character set – Java retrieves char data (bytes) from UTF8 db  Converts to UCS2 (Unicode) – Java code generates HTML – Client browser displays Kanji characters  Netscape, “Japanese (Auto-Detect)” char set  Application still works – bytes in UTF8 db don’t represent UTF8 encoded Kanji

24 Brian Hitchcock November 13, 2003Page 24 NoCOUG www.brianhitchcock.net Application Works (?) Netscape Browser Character set UTF8 Oracle Db Application Retrieves character data Converts UTF8 to UCS2 Generate HTML Send HTML to client browser Browser detects multi-byte characters, displays Kanji character ISO1UCS2ISO1UTF8 Japanese Auto-Detect 8859-1 0xC2B0, 0xC2A1 0xB0, 0xA1 EUC-JP character code for this character is 0xB0A1 Export WE database, import into UTF8 db

25 Brian Hitchcock November 13, 2003Page 25 NoCOUG www.brianhitchcock.net Test Application  Insert bytes for correctly encoded Kanji – Into UTF8 db – Use CHR() function  Display this data using existing application – Does NOT display Kanji!  Using “Japanese (Auto-Detect)” character set – Try Netscape UTF8 character set  Doesn’t display Kanji – UTF8 character set should work, shouldn’t it?

26 Brian Hitchcock November 13, 2003Page 26 NoCOUG www.brianhitchcock.net Where Are We?  Correctly encoded UTF8 multi-byte character data for Kanji does not work with existing application  Simply “converting” (export WE, import to UTF8) doesn’t result in correctly encoded UTF8 character data  Need to figure out what app code is doing – Whoever wrote it is gone – The usual state of affairs

27 Brian Hitchcock November 13, 2003Page 27 NoCOUG www.brianhitchcock.net How To Debug App Code?  Don’t use app code – write very simple Java Servlet  (The Java Diva helps with this…) – Servlet simply retrieves character data from db  Runs in iPlanet web server – generates HTML for client browser  Use servlet to retrieve correct UTF8 Kanji – Does not display Kanji!  Fix servlet then can fix application code?

28 Brian Hitchcock November 13, 2003Page 28 NoCOUG www.brianhitchcock.net Modified Servlet Code res.setContentType("text/html;charset=UTF-8"); PrintWriter out = new PrintWriter( new OutputStreamWriter(res.getOutputStream(), "UTF-8"),true); out.println("");

29 Brian Hitchcock November 13, 2003Page 29 NoCOUG www.brianhitchcock.net Fix Application  Make same changes to application code  Browser displays Kanji correctly – Manually generated, correctly encoded UTF8  Application interacts with Dynamo – Need to reconfigure Dynamo for UTF8 data  Application fixed (?) – Works with correctly encoded UTF8 multi-byte data

30 Brian Hitchcock November 13, 2003Page 30 NoCOUG www.brianhitchcock.net Is Application really fixed?  Fixed app retrieves correctly encoded UTF8 character data  What about existing character data? – Data that was exported from WE and imported into UTF8 db  Use fixed app code to retrieve existing data – Existing Kanji are not displayed  Original app did display existing data... – Existing data is not correctly encoded UTF8

31 Brian Hitchcock November 13, 2003Page 31 NoCOUG www.brianhitchcock.net Fixed Application Netscape Browser Character set UTF8 Oracle Db Application Retrieves character data Converts UTF8 to UCS2 Generate HTML Send HTML to client browser Browser displays characters for the UTF8 bytes 0xC2B0, 0xC2A1 which are degree sign and upside down exclamation point UTF8UCS2UTF8 UTF8t 8859-1 0xC2B0, 0xC2A1 0xB0, 0xA10xC2B0, 0xC2A1 EUC-JP character code for this character is 0xB0A1 °¡

32 Brian Hitchcock November 13, 2003Page 32 NoCOUG www.brianhitchcock.net How To Fix Existing Data?  What’s wrong with existing data (UTF8 db) – Character data is not correctly encoded UTF8 – It is UTF8 encoded Unicode of each single byte that was exported from WE database  Before importing into UTF8 database? – EUC-JP character set (Latin ASCII and Kanji) – Stored in single-byte WE database  Need to convert UTF8 of WE of EUC-JP to correct UTF8 bytes for Kanji

33 Brian Hitchcock November 13, 2003Page 33 NoCOUG www.brianhitchcock.net Review of Bytes is Bytes  Original Kanji character 0xB0A1 (EUC-JP)  Inserted into Oracle database – 0xB0, 0xA1 in WE8ISO8859P1 db  Exported/imported into Oracle UTF8 db – Individual bytes converted to UTF8  Original Kanji character was 2 bytes  Became 4 bytes in UTF8 db  0xC2B0, 0xC2A1  Correct UTF8 bytes are 0xE4BA9C

34 Brian Hitchcock November 13, 2003Page 34 NoCOUG www.brianhitchcock.net How to Convert Existing Data?  Fix in Oracle WE before export/import – No point, export/import will ‘corrupt’ character data, will need to fix after export/import  Don’t export/import – SQL select each table to flat files from WE db – SQL*Loader into UTF8 database  Use CHARACTERSET JA16EUC option  More work moving each table one at a time

35 Brian Hitchcock November 13, 2003Page 35 NoCOUG www.brianhitchcock.net SQL*Loader Option SQL Select to flat file for each table Netscape Browser 0xE4BA9C Character set UTF8 SQL*Loader CHARACTERSET JA16EUC 0xB0A1 Oracle Db 0xB0A1 Application Oracle Db character set WE8ISO8859P1 0xB0A1 EUC-JP character code for this character is 0xB0A1 Select “UTF8” character set to view Kanji characters Application retrieves char data generates HTML

36 Brian Hitchcock November 13, 2003Page 36 NoCOUG www.brianhitchcock.net Convert Existing Data  Fix data after import into UTF8 database – Export from WE, import into UTF8 database – Use Oracle SQL CONVERT() function  CONVERT() from UTF8 to WE8ISO8859P1  CONVERT() from JA16EUC to UTF8 – Need to CONVERT() each column of each table that contains multi-byte data  How to be sure which columns to CONVERT()?  CONVERT() all columns that contain char data? – Must test using CONVERT() to verify it works

37 Brian Hitchcock November 13, 2003Page 37 NoCOUG www.brianhitchcock.net Fix After Import Application Oracle Db character set WE8ISO8859P1 Export File Import loads export file character set WE8ISO8859P1 0xB0A1 0xB0, 0xA1 EUC-JP character code for this character is 0xB0A1 Application Oracle Db character set UTF8 0xC2B0, 0xC2A1 Convert from UTF8 to WE8ISO8859P1 Convert from EUC-JP to UTF8 0xE4BA9C Bytes of original EUC-JP Kanji character Correctly encoded UTF8 bytes for this Kanji are 0xE4BA9C

38 Brian Hitchcock November 13, 2003Page 38 NoCOUG www.brianhitchcock.net Oracle CONVERT()  Syntax, examples – select CONVERT(,, )  select CONVERT(, WE8ISO8859P1, UTF8)  select CONVERT(, UTF8, JA16EUC) – Don’t re-run CONVERT() without testing  re-run may corrupt data  regenerate original source data, re-run CONVERT()

39 Brian Hitchcock November 13, 2003Page 39 NoCOUG www.brianhitchcock.net Overall Conversion Process  What we did… – Identify tables/columns contain multi-byte data – Export from WE database – Import into UTF8 database  rows=n, create tables, don’t load data – Widen columns for UTF8 multi-byte data  increase to 3 times original width – Import into UTF8 database (again)  ignore=y, load data into existing tables

40 Brian Hitchcock November 13, 2003Page 40 NoCOUG www.brianhitchcock.net Overall Conversion Process  Continued – CONVERT() columns that contain multi-byte data – Test, compare with data from existing application/data  Conversion includes converting all pieces of the application, not just the Oracle database

41 Brian Hitchcock November 13, 2003Page 41 NoCOUG www.brianhitchcock.net Details - Source Char Set?  How did I determine this? – Original Kanji data was from EUC-JP – How was this determined?  Examine bytes of original character data  Display Original Kanji characters  Find single Kanji in Japanese dictionary ­Gives row-cell code of Kanji in JIS-0208  Using other reference sources ­manually generate bytes for the Kanji in various encodings  Compare with bytes of original Kanji data

42 Brian Hitchcock November 13, 2003Page 42 NoCOUG www.brianhitchcock.net Rosetta Stone? Oracle8i National Language Support Guide Release 2 (8.1.6) December 1999 Part No. A76966-01 page 3-22

43 Brian Hitchcock November 13, 2003Page 43 NoCOUG www.brianhitchcock.net Reference Books Used The New Nelson Japanese-English Character Dictionary By John H. Haig,Andrew N. Nelson Published by Periplus Editions, Ltd Date Published: 11/1996 ISBN: 0804820368 The Unicode Standard: With CD-ROM By Unicode Consortium Published by Addison Wesley Longman, Inc. Date Published: 04/1995 ISBN: 0201483459 CJKV Information Processing By Ken Lunde,Gigi Estabrook (Editor) Published by O'Reilly & Associates, Incorporated Date Published: 01/1999 ISBN: 1565922247

44 Brian Hitchcock November 13, 2003Page 44 NoCOUG www.brianhitchcock.net Lessons Learned  Oracle (and Sybase) don’t store characters – They store bytes, strings of bytes  Normally, Oracle does NO checking of character set – does NOT check that bytes inserted represent correct characters in database character set  Only under specific circumstances does Oracle “apply” a character set to char data  Changing character set affects more than just the database

45 Brian Hitchcock November 13, 2003Page 45 NoCOUG www.brianhitchcock.net Lessons Learned  Bytes of character from any char set can be stored in db of any charset – EUC-JP char in WE db, in UTF8 db – bytes in db are not ‘correct’ bytes for the character in the db character set – all apps, users, dbs must know that db contains char data from other char set – Any char set conversion may corrupt the char data -- import WE into UTF8 db

46 Brian Hitchcock November 13, 2003Page 46 NoCOUG www.brianhitchcock.net Lessons Learned  Simply exporting db, importing into UTF8 does not solve the problems  Testing requires generating correctly encoded character data  Every piece of an application makes a decision about character set (default)  If all data in db really is in the db char set – export, import to db of other char set works  Need to see original character data – Verify data after char set conversion


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