How do I change a MySQL table to UTF-8? - mysql

Question

I know there are many settings for a language for a table and a database.
I already created the database. I believe when I created it, it was default/LATIN. I want to change everything-I mean...both the table and the database, to UTF-8.
How can I do that? thanks.

Answer 1

ALTER TABLE tbl_name CONVERT TO CHARACTER SET utf8;

Answer 2

Have a look at Using alter command to change character set.
Another useful link: http://dev.mysql.com/doc/refman/5.0/en/charset-table.html
The general form is
ALTER DATABASE db_name
[[DEFAULT] CHARACTER SET charset_name]
[[DEFAULT] COLLATE collation_name]
and for a specific column in a table
ALTER TABLE column COLLATE utf8_general_ci
MySQL’s character sets and collations demystified
MySQL Forums :: Change Collation

Answer 3

aioobe's answer tells how to change the character set of a database, table or column. You should keep in mind that
setting the character set for a table just specifies the default character set for new columns in that table. It doesn't change the character set for preexisting columns; you have to do those columns individually, OR if you want to change every single string-type column in the table to the same character set there's a command you can use to do that: "alter table ... convert to character set" ( http://dev.mysql.com/doc/refman/5.1/en/alter-table.html )
if you already have data that is stored mis-encoded in a column, then using "alter table ... modify" to change the column will not quite solve the problem. For example, if you're been storing UTF-8 data in a Latin1 column and you change the character set directly from Latin1 to UTF-8, it'll still be mis-encoded afterwards. This can be worked around by converting from Latin-1 to UTF-8 via binary.

Answer 4

1) Database default character set and collation:
SELECT ##character_set_database, ##collation_database;
Altered via: ALTER DATABASE CHARACTER SET utf8 COLLATE utf8_general_ci;
2) Table default character set and collation:
SELECT T.table_name, 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 = "YOUR_DB";`
Altered via: ALTER TABLE [table_name] CHARACTER SET utf8 COLLATE utf8_general_ci
3) Column character set and collation:
SELECT c.TABLE_NAME, c.COLUMN_NAME, c.CHARACTER_SET_NAME, c.COLLATION_NAME
FROM information_schema.COLUMNS c
WHERE c.table_schema = "YOUR_DB";`
Altered via: ALTER TABLE [table_name] CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci
The third one requires that you disable foreign key checks for the data conversion. So putting this all together:
DELIMITER //
CREATE PROCEDURE migrate_charset_to_utf8()
BEGIN
DECLARE done TINYINT DEFAULT 0;
DECLARE curr_table VARCHAR(64);
DECLARE table_cursor CURSOR FOR
SELECT T.table_name
FROM information_schema.TABLES T
WHERE T.TABLE_TYPE = 'BASE TABLE' AND
T.TABLE_SCHEMA = 'YOUR_DB';
DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = 1;
OPEN table_cursor;
table_loop: LOOP
FETCH table_cursor INTO curr_table;
IF done THEN
LEAVE table_loop;
END IF;
# Convert table data(columns) charset
SET #sql_str1 = CONCAT("ALTER TABLE ", curr_table, " CONVERT TO CHARACTER SET utf8 COLLATE utf8_general_ci");
PREPARE stmt1 FROM #sql_str1;
EXECUTE stmt1;
DEALLOCATE PREPARE stmt1;
# Set table's default charset e.g for new columns added
SET #sql_str2 = CONCAT("ALTER TABLE ", curr_table, " CHARACTER SET utf8 COLLATE utf8_general_ci");
PREPARE stmt2 FROM #sql_str2;
EXECUTE stmt2;
DEALLOCATE PREPARE stmt2;
END LOOP table_loop;
CLOSE table_cursor;
END//
DELIMITER ;
SET ##FOREIGN_KEY_CHECKS = 0;
CALL migrate_charset_to_utf8();
SET ##FOREIGN_KEY_CHECKS = 1;
ALTER DATABASE CHARACTER SET utf8 COLLATE utf8_general_ci;
EDIT: look here instead

Answer 5

Add to your my.cnf this:
[mysqld]
character-set-server=utf8
default-collation=utf8_unicode_ci
And restart mysqld deamon.
ADDED:
ALTER DATABASE your_base_name CHARACTER SET utf8 COLLATE utf8_unicode_ci;
and my.cnf
SET collation_connection = utf8_unicode_ci;
SET character_set_results = utf8;
SET character_set_connection = utf8;
SET character_set_client = utf8;