I've recently taken over an old project that was created 10 years ago. It uses MySQL 5.1.
Among other things, I need to change the default character set from latin1 to utf8.
As an example, I have tables such as this:
CREATE TABLE `users` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`first_name` varchar(45) CHARACTER SET latin1 COLLATE latin1_general_ci DEFAULT NULL,
`last_name` varchar(45) CHARACTER SET latin1 COLLATE latin1_general_ci DEFAULT NULL,
`username` varchar(127) CHARACTER SET latin1 COLLATE latin1_general_ci NOT NULL,
`email` varchar(127) CHARACTER SET latin1 COLLATE latin1_general_ci NOT NULL,
`pass` varchar(20) CHARACTER SET latin1 COLLATE latin1_general_ci NOT NULL,
`active` char(1) CHARACTER SET latin1 COLLATE latin1_general_ci NOT NULL DEFAULT 'Y',
`created` datetime NOT NULL,
`last_login` datetime DEFAULT NULL,
`author` varchar(1) CHARACTER SET latin1 COLLATE latin1_general_ci DEFAULT 'N',
`locked_at` datetime DEFAULT NULL,
`created_at` datetime DEFAULT NULL,
`updated_at` datetime DEFAULT NULL,
`ripple_token` varchar(36) CHARACTER SET latin1 COLLATE latin1_general_ci DEFAULT NULL,
`ripple_token_expires` datetime DEFAULT '2014-10-31 08:03:55',
`authentication_token` varchar(255) CHARACTER SET latin1 COLLATE latin1_general_ci DEFAULT NULL,
PRIMARY KEY (`id`),
UNIQUE KEY `index_users_on_reset_password_token` (`reset_password_token`),
UNIQUE KEY `index_users_on_confirmation_token` (`confirmation_token`),
UNIQUE KEY `index_users_on_unlock_token` (`unlock_token`),
KEY `users_active` (`active`),
KEY `users_username` (`username`),
KEY `index_users_on_email` (`email`)
) ENGINE=InnoDB AUTO_INCREMENT=1677 DEFAULT CHARSET=utf8 CHECKSUM=1 DELAY_KEY_WRITE=1 ROW_FORMAT=DYNAMIC
I set up my own Mac to work on this. Without thinking too much about it, I ran "brew install mysql" which installed MySQL 5.7. So I have some version conflicts.
I downloaded a copy of this database and imported it.
If I try to run a query like this:
ALTER TABLE users MODIFY first_name varchar(45) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL
I get this error:
ERROR 1292 (22007): Incorrect datetime value: '0000-00-00 00:00:00' for column 'created' at row 1
I thought I could fix this with:
ALTER TABLE users MODIFY created datetime NULL DEFAULT '1970-01-01 00:00:00';
Query OK, 0 rows affected (0.06 sec)
Records: 0 Duplicates: 0 Warnings: 0
but I get:
ALTER TABLE users MODIFY first_name varchar(45) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL ;
ERROR 1292 (22007): Incorrect datetime value: '0000-00-00 00:00:00' for column 'created' at row 1
Do I have to update every value?
My suggestion if it is the case that the table is empty or not very very big is to export the create statements as a .sql file, rewrite them as you wish. Also do the same if you have any existing data, i.e. export insert statements (I recommend doing this in a separate file as the create statements). Finally, drop the table and execute first create statement and then inserts.
You can use for that either mysqldump command, included in your MySQL installation or you can also install MySQL Workbench, which is a free graphical tool that includes also this option in a very customisable way without having to look for specific command options.