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brianhitchcock

www.brianhitchcock.net. Brian Hitchcock OCP DBA 8i Global Sales IT Sun Microsystems brian.hitchcock@sun.com brhora@aol.com. www.brianhitchcock.net. Session #403 NLS and The Case of the Missing Kanji. NLS -- National Language Support Kanji -- Japanese characters. www.brianhitchcock.net.

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brianhitchcock

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  1. www.brianhitchcock.net

  2. Brian HitchcockOCP DBA 8i Global Sales IT Sun Microsystems brian.hitchcock@sun.com brhora@aol.com www.brianhitchcock.net

  3. Session #403 NLS and The Case of the Missing Kanji NLS -- National Language Support Kanji -- Japanese characters www.brianhitchcock.net

  4. 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

  5. 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?

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

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

  8. Moving Sybase Data to Oracle • What happened? • Oracle database is US7ASCII character set • 7-bits per character • Import 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

  9. 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 3021 0! Hex Decimal Binary A 10 1010 B 11 1011 C 12 1100 D 13 1101 E 14 1110 F 15 1111 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 ! EUC-JP character code for this character is 0xB0A1

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

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

  12. 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

  13. Retrieves character data Converts 8859-1 to UCS2 Generate HTML Send HTML to client browser UCS2 Netscape Browser Existing Application Application 8859-1 ISO1 ISO1 UCS2 -- 2 byte Unicode Oracle Db Japanese Auto-Detect 8859-1 Character set WE8ISO8859P1 Browser detects multi-byte characters, displays Kanji character

  14. Existing Application • Each piece of software makes some decision (default) about character set • You need to understand this process for your application

  15. 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

  16. 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

  17. 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?

  18. 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?

  19. UTF8 Encoding Process JA16EUC to UTF8 ConversionJA16EUC 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 • Think your life is boring? Metalink Doc ID: Note:69518.1 Determining the codepoint for UTF8 characters

  20. Unicode UCS2 ISO-2022-JP Shift-JIS JIS UTF8 EUC-JP Bytes is Bytes ISO-2022-JP character code for this character is 0x3021 Unicode byte code for this character is 0x4E9C Unicode lookup table Formula Formula Formula Formula JIS row/cell values for this character are Row 16, Column 1 Shift-JIS byte code for this character is 0x889F UTF8 byte code for this character is 0xE4BA9C EUC-JP byte code for this character is 0xB0A1 Kanji character encodings shown for the various character sets

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

  22. 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

  23. 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! (?)

  24. 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

  25. 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

  26. Retrieves character data Converts UTF8 to UCS2 Generate HTML Send HTML to client browser Netscape Browser Application Works (?) Application 0xB0, 0xA1 0xB0, 0xA1 0xB0, 0xA1 UTF8 UCS2 ISO1 ISO1 0xB0, 0xA1 0xC2B0, 0xC2A1 Oracle Db Export WE database, import into UTF8 db 8859-1 Japanese Auto-Detect Character set UTF8 Browser detects multi-byte characters, displays Kanji character EUC-JP character code for this character is 0xB0A1

  27. 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?

  28. 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

  29. 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?

  30. Modified Servlet Code res.setContentType("text/html;charset=UTF-8"); PrintWriter out = new PrintWriter( new OutputStreamWriter(res.getOutputStream(), "UTF-8"),true); out.println("<META HTTP-EQUIV=" + DQ + "Content-Type" + DQ + " CONTENT=" + DQ + "text/html; charset=utf-8" + DQ + ">");

  31. 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

  32. 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

  33. Retrieves character data Converts UTF8 to UCS2 Generate HTML Send HTML to client browser Netscape Browser Fixed Application Application 0xB0, 0xA1 0xC2B0, 0xC2A1 UTF8 UCS2 UTF8 UTF8 0xC2B0, 0xC2A1 0xC2B0, 0xC2A1 Oracle Db UTF8t 8859-1 EUC-JP character code for this character is 0xB0A1 Browser displays characters for the UTF8 bytes 0xC2B0, 0xC2A1 which are degree sign and upside down exclamation point Character set UTF8 °¡

  34. 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

  35. 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

  36. 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

  37. Application retrieves char data generates HTML Application Oracle Db character set WE8ISO8859P1 SQL*Loader CHARACTERSET JA16EUC Netscape Browser SQL*Loader Option 0xE4BA9C Oracle Db 0xB0A1 Character set UTF8 0xB0A1 0xB0A1 SQL Select to flat file for each table 0xB0A1 EUC-JP character code for this character is 0xB0A1 Select “UTF8” character set to view Kanji characters 0xE4BA9C

  38. 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

  39. Application Oracle Db character set WE8ISO8859P1 Application Oracle Db character set UTF8 Import loads export file character set WE8ISO8859P1 Convert from UTF8 to WE8ISO8859P1 Convert from EUC-JP to UTF8 Export File Fix After Import 0xB0A1 0xC2B0, 0xC2A1 0xB0, 0xA1 Bytes of originalEUC-JP Kanji character 0xE4BA9C 0xB0A1 0xB0, 0xA1 Correctly encoded UTF8 bytes for this Kanji are 0xE4BA9C EUC-JP character code for this character is 0xB0A1

  40. Oracle CONVERT() • Syntax, examples • select CONVERT(<column>, <destination char set>, <source char set>) • select CONVERT(<column>, WE8ISO8859P1, UTF8) • select CONVERT(<column>, UTF8, JA16EUC) • Don’t re-run CONVERT() without testing • re-run may corrupt data • regenerate original source data, re-run CONVERT()

  41. 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

  42. 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

  43. 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

  44. Rosetta Stone? Oracle8i National Language Support Guide Release 2 (8.1.6) December 1999 Part No. A76966-01 page 3-22

  45. 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

  46. 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

  47. 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

  48. 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

  49. Fill Out a Survey and Get a Chance to Win a Compaq iPAQ! We want to know what you think! Fill out the survey that was handed out at the beginning of the session for a chance to win a Compaq iPAQ. Remember to include your name and email in the available section and we will enter your name into two daily drawings to win an iPAQ

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