106
votes

One of the responses to a question I asked yesterday suggested that I should make sure my database can handle UTF-8 characters correctly. How I can do this with MySQL?

14
I really hope we get a comprehensive answer, covering various MySQL versions, incompatibilities, etc.Edward Z. Yang
@EdwardZ.Yang -- MySQL 4.1 introduced CHARACTER SETs; 5.1.24 messed with the collation of German sharp-s (ß), which was rectified by adding another collation in 5.1.62 (arguably making things worse); 5.5.3 filled out utf8 with the new charset utf8mb4.Rick James
This question is quite same to this one.. Please look at that stackoverflow.com/questions/3513773/…Nyein Aung
It's worth pointing out that most of these answers are just plain wrong. Do not use utf8. It only supports up to 3-byte characters. The correct character set you should use in MySQL is utf8mb4.SineSwiper

14 Answers

94
votes

Update:

Short answer - You should almost always be using the utf8mb4 charset and utf8mb4_unicode_ci collation.

To alter database:

ALTER DATABASE dbname CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

See:

Original Answer:

MySQL 4.1 and above has a default character set of UTF-8. You can verify this in your my.cnf file, remember to set both client and server (default-character-set and character-set-server).

If you have existing data that you wish to convert to UTF-8, dump your database, and import it back as UTF-8 making sure:

  • use SET NAMES utf8 before you query/insert into the database
  • use DEFAULT CHARSET=utf8 when creating new tables
  • at this point your MySQL client and server should be in UTF-8 (see my.cnf). remember any languages you use (such as PHP) must be UTF-8 as well. Some versions of PHP will use their own MySQL client library, which may not be UTF-8 aware.

If you do want to migrate existing data remember to backup first! Lots of weird choping of data can happen when things don't go as planned!

Some resources:

46
votes

To make this 'permanent', in my.cnf:

[client]
default-character-set=utf8
[mysqld]
character-set-server = utf8

To check, go to the client and show some variables:

SHOW VARIABLES LIKE 'character_set%';

Verify that they're all utf8, except ..._filesystem, which should be binary and ..._dir, that points somewhere in the MySQL installation.

32
votes

MySQL 4.1 and above has a default character set that it calls utf8 but which is actually only a subset of UTF-8 (allows only three-byte characters and smaller).

Use utf8mb4 as your charset if you want "full" UTF-8.

20
votes

The short answer: Use utf8mb4 in 4 places:

  • The bytes in your client are utf8, not latin1/cp1251/etc.
  • SET NAMES utf8mb4 or something equivalent when establishing the client's connection to MySQL
  • CHARACTER SET utf8mb4 on all tables/columns -- except columns that are strictly ascii/hex/country_code/zip_code/etc.
  • <meta charset charset=UTF-8> if you are outputting to HTML. (Yes the spelling is different here.)

More info ;
UTF8 all the way

The above links provide the "detailed canonical answer is required to address all the concerns". -- There is a space limit on this forum.

Edit

In addition to CHARACTER SET utf8mb4 containing "all" the world's characters, COLLATION utf8mb4_unicode_520_ci is arguable the 'best all-around' collation to use. (There are also Turkish, Spanish, etc, collations for those who want the nuances in those languages.)

4
votes

The charset is a property of the database (default) and the table. You can have a look (MySQL commands):

show create database foo; 
> CREATE DATABASE  `foo`.`foo` /*!40100 DEFAULT CHARACTER SET latin1 */

show create table foo.bar;
> lots of stuff ending with
> ) ENGINE=InnoDB AUTO_INCREMENT=252 DEFAULT CHARSET=latin1

In other words; it's quite easy to check your database charset or change it:

ALTER TABLE `foo`.`bar` CHARACTER SET utf8;
3
votes

I followed Javier's solution, but I added some different lines in my.cnf:

[myslqd]
skip-character-set-client-handshake
collation_server=utf8_unicode_ci
character_set_server=utf8 

I found this idea here: http://dev.mysql.com/doc/refman/5.0/en/charset-server.html in the first/only user comment on the bottom of the page. He mentions that skip-character-set-client-handshake has some importance.

3
votes

To change the character set encoding to UTF-8 for the database itself, type the following command at the mysql> prompt. USE ALTER DATABASE.. Replace DBNAME with the database name:

ALTER DATABASE DBNAME CHARACTER SET utf8 COLLATE utf8_general_ci;

This is a duplicate of this question How to convert an entire MySQL database characterset and collation to UTF-8?

0
votes

These tips on MySQL and UTF-8 may be helpful. Unfortunately, they don't constitute a full solution, just common gotchas.

0
votes

Set your database collation to UTF-8 then apply table collation to database default.

-1
votes

Your answer is you can configure by MySql Settings. In My Answer may be something gone out of context but this is also know is help for you.
how to configure Character Set and Collation.

For applications that store data using the default MySQL character set and collation (latin1, latin1_swedish_ci), no special configuration should be needed. If applications require data storage using a different character set or collation, you can configure character set information several ways:

  • Specify character settings per database. For example, applications that use one database might require utf8, whereas applications that use another database might require sjis.
  • Specify character settings at server startup. This causes the server to use the given settings for all applications that do not make other arrangements.
  • Specify character settings at configuration time, if you build MySQL from source. This causes the server to use the given settings for all applications, without having to specify them at server startup.

The examples shown here for your question to set utf8 character set , here also set collation for more helpful(utf8_general_ci collation`).

Specify character settings per database

  CREATE DATABASE new_db
  DEFAULT CHARACTER SET utf8
  DEFAULT COLLATE utf8_general_ci;

Specify character settings at server startup

[mysqld]
character-set-server=utf8
collation-server=utf8_general_ci

Specify character settings at MySQL configuration time

shell> cmake . -DDEFAULT_CHARSET=utf8 \
           -DDEFAULT_COLLATION=utf8_general_ci

To see the values of the character set and collation system variables that apply to your connection, use these statements:

SHOW VARIABLES LIKE 'character_set%';
SHOW VARIABLES LIKE 'collation%';

This May be lengthy answer but there is all way, you can use. Hopeful my answer is helpful for you. for more information http://dev.mysql.com/doc/refman/5.7/en/charset-applications.html

-2
votes

SET NAMES UTF8

This is does the trick

-2
votes

DATABASE CONNECTION TO UTF-8

$connect = mysql_connect('$localhost','$username','$password') or die(mysql_error());
mysql_set_charset('utf8',$connect);
mysql_select_db('$database_name','$connect') or die(mysql_error());
-3
votes

Set your database connection to UTF8:

  if($handle = @mysql_connect(DB_HOST, DB_USER, DB_PASS)){          
         //set to utf8 encoding
         mysql_set_charset('utf8',$handle);
  }
-3
votes

Was able to find a solution. Ran the following as specified at http://technoguider.com/2015/05/utf8-set-up-in-mysql/

SET NAMES UTF8;
set collation_server = utf8_general_ci;
set default-character-set = utf8;
set init_connect = ’SET NAMES utf8′;
set character_set_server = utf8;
set character_set_client = utf8;