Gittu's Blog

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Mysql Utf/latin Collation and Bangla Nightmare

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Those who maintain a non-english/bangla blog, forum or site, this type of problems are kinda common. The most common problem is seeing ??????, and fix: go and change collation to utf8 [grin] But my problem started from this simple (yes it looked simple [confused] ) problem but ended up a nightmare.

I was running a ipboard instance. When importing a bangla translation, the text was showing as ??????, so i applied the common fix, changed all table and field collation to utf8_unicode_ci and ipb's encoding to utf8. Now the site became inaccessible, showing a preety "Fatal ERROR : Your settings could not be read by IP.Board". That was fixed by running ipb's upgradeFinish script but the real problem starts now.

The Problem:

All bangla letters became this :


Looks pretty right ? :v

The reason behind this was all bangla chars were inserted in mysql using latin1 encoding. If I set mysql client's encoding to latin1 and read, i get real bangla. If I set encoding to utf8 and read, i get latin-fied bangla like the picture.

Failed Attempts:

I immediately went on a long google search and tried several solutions, but unfortunately, none of them were able to solve the problem completely. These two links (1 2) were a great help though, which helped to understand the problem thoroughly.

The solution proposed in first link, was a partial success. Change the fields in squence of utf8 > latin1 > blob > utf8. The trick in converting to blob is it fools mysql to convert latin1 to utf8 without running any conversion algorithm. It works when checking a single field, but not for all, the whole database of ipb is kinda complex. Some field were primary field and mysql not allows them to altered to blob. I ran a script to loop through all table,all field and alter them but ended up with a bunch of error and corrupted database.

Then i changed my focus to the mysql dump file. If i can change the latin text inside the sql file to unicode text, problem will be gone. I tried enca(1) but it failed to change anything. Tried recode(1) without any success.

Then i created a script in php to read the whole sql line by line and feed them through utf8_encode. Which made the unreadable latin text to unreadable capital letter latin.

That was a mistake, actually i need to use utf8_decode. So now, the texts were back to bangla, but also many(almost all) chars are missing. Only first letter of a word or one word of a sentence was there, the rest vanished into the wind.

Next, tried iconv(1) which striped away half of the database [frown]

The Real Solution:

The idea is to insert the db to mysql as latin1, dump the db as latin1. Edit the dump to change it to utf8 and insert it as utf8.

  1. First task is to insert the mysqldump in latin1 encoding and in latin1 collation. So i took a bit help from sed.
    sed -i 's/CHARSET=utf8 COLLATE=utf8_unicode_ci/CHARSET=latin1/g' database.sql
    sed -i 's/COLLATE utf8_unicode_ci/COLLATE latin1_bin/g' database.sql
  2. Now i inserted this database.sql into mysql. Now we need to extract it as latin1, so applying --default-character-set=latin1 flag.

    mysqldump --default-character-set=latin1 -u user -p dbname > database_latin.sql
    I opened the database_latin.sql and saw the text was written in bangla. [grin]

  3. Now we need to edit the dump file and change it to utf8, as we are gonna insert it as utf8 now. again, sed to rescue.

    sed -i 's/SET NAMES latin1/SET NAMES utf8/g' database_latin.sql
    sed -i 's/CHARSET=latin1/CHARSET=utf8 COLLATE=utf8_unicode_ci/g' database_latin.sql
    sed -i 's/COLLATE latin1_bin/COLLATE utf8_unicode_ci/g' database_latin.sql
    sed -i 's/CHARACTER SET latin1/CHARACTER SET utf8/g' database_latin.sql

  4. Finally i inserted this database_latin.sql to mysql and voila [grin] no error, clear bangla and no chars missing [grin]

Ending Thoughts:

If you are making a bangla or non-english site, always start with a proper collation setting. Set all table and field collation to utf8_unicode_ci or utf8_general_ci. Make sure the mysql client (your app) speaks in utf8. If you are running raw mysql query, run set names utf8 at beginning. If using a framework or toolkit, check where to set this utf8 config. These will save you from infinite PITA later.

If you indeed missed the utf8 config and ended up in a mess like me, try to apply a solution that doesn't directy convert the encoding of the texts. You may end up with missing or corrupted chars.

NB: If you are following this post, dont copy-paste the commands, understand and adept the commands to your scenario. Forgive my poor writing and let me know your thoughts in the comment section.