Converting a MySQL database to UTF-8

Learn how to convert a MySQL database's character set to UTF-8 encoding with this guide including instructions, relevant code snippets, and links to related articles.

This article describes how to convert a MySQL database's character set to UTF-8 encoding (also known as Unicode). The UTF-8 character encoding set supports many alphabets and characters for a wide variety of languages.

Although MySQL supports the UTF-8 character encoding set, it is often not used as the default character set during database and table creation. As a result, many databases use the Latin character set, which can be limiting depending upon the application.

Determining the current character encoding set

To determine which character encoding set a MySQL database or table is currently using:

  1. Log in to your account using SSH.

  2. At the command line, type the following command, replacing username with your username:

    mysql -u username -p
    
  3. At the Enter Password prompt, type your password. When you type the correct password, the mysql> prompt appears.

  4. To display the current character encoding set for a particular database, type the following command at the mysql> prompt. Replace dbname with the database name:

    SELECT default_character_set_name FROM information_schema.SCHEMATA S WHERE schema_name = "dbname";
    
  5. To display the current character encoding set for a particular table in a database, type the following command at the mysql> prompt. Replace dbname with the database name, and tablename with the name of the table:

    SELECT CCSA.character_set_name FROM information_schema.`TABLES` T,information_schema.`COLLATION_CHARACTER_SET_APPLICABILITY` CCSA WHERE CCSA.collation_name = T.table_collation AND T.table_schema = "dbname" AND T.table_name = "tablename";
    
  6. To exit the mysql program, type \q at the mysql> prompt.

Converting the character encoding set to UTF-8

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Warning

Make sure that you back up the database before you start this procedure! You can back up a MySQL database using cPanel, phpMyAdmin, or the mysqldump program.

To convert the character encoding set to UTF-8:

  1. Log in to your account using SSH.

  2. Create a text file named .my.cnf. To do this, you can use a text editor such as Vim or Nano. This procedure shows how to use Nano. At the command line, type the following command:

    nano .my.cnf
    
  3. Add the following lines to the file, replacing username with your username and password with your password (make sure the password is enclosed in quotation marks):

    [client]
    user=username
    password="password"
    
  4. When the edits are complete, press Ctrl+X, type y to save the file, and then press Enter.

  5. To change the character set encoding to UTF-8 for all of the tables in the specified database, type the following command at the command line. Replace dbname with the database name:

    mysql --database=dbname -B -N -e "SHOW TABLES" | awk '{print "SET foreign_key_checks = 0; ALTER TABLE", $1, "CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci; SET foreign_key_checks = 1; "}' | mysql --database=dbname
    
  6. After the command finishes, type the following command to start the mysql program:

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

    ALTER DATABASE dbname CHARACTER SET utf8 COLLATE utf8_general_ci;
    
  8. To exit the mysql program, type \q at the mysql> prompt.

  9. To delete the .my.cnf file, type the following command at the command line:

    rm .my.cnf
    
  10. To verify that the character set encoding is now set to UTF-8, follow the steps in the Determining the current character encoding set procedure above.

More Information

For more information about UTF-8 and Unicode, please visit http://en.wikipedia.org/wiki/UTF-8.

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