Is there any shorter equivalent for the following query: (I can not alter the table). Are cast operators applicable here?
select convert(old_text using utf8) as text,
convert(rev_timestamp using utf8) as ts,
convert(rev_user_text using utf8) as user from revision;
Update: The table schema is:
CREATE TABLE `revision` (
`rev_id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`rev_page` INT(10) UNSIGNED NOT NULL,
`rev_text_id` INT(10) UNSIGNED NOT NULL,
`rev_comment` TINYBLOB NOT NULL,
`rev_user` INT(10) UNSIGNED NOT NULL DEFAULT '0',
`rev_user_text` VARCHAR(255) NOT NULL DEFAULT '' COLLATE 'latin1_bin',
`rev_timestamp` BINARY(14) NOT NULL DEFAULT '\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0',
`old_id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
`old_text` MEDIUMBLOB NOT NULL,
`old_flags` TINYBLOB NOT NULL,
)
COLLATE='latin1_swedish_ci'
ENGINE=InnoDB
the best is to alter your table and set utf8 for your needed columns instead of everytime converting them
ALTER TABLE t MODIFY old_text CHAR(50) CHARACTER SET utf8;
ALTER TABLE t MODIFY rev_timestamp CHAR(50) CHARACTER SET utf8;
ALTER TABLE t MODIFY rev_user_text CHAR(50) CHARACTER SET utf8;
and then select them normal.
select old_text as text, rev_timestamp as ts, rev_user_text as user
from revision;
note: about char(50) change it to your needs.
set names utf8;
SELECT old_text AS text, rev_timestamp AS ts, rev_user_text AS user
FROM revisions;
...but this will break if you are sending DML in a different character set.
The easiest way to modify, is to modify the my.ini file in mysql character set key,
default-character-set = utf8
character_set_server = utf8
After modification, restart the mysql service, service mysql restart
Related
By my ignorance, I have altered a few tables without specifying collation.
That caused changed columns, which used to be latin1 characters, to be changed to utf8mb4.
This brought HUGE performance loss running joins. And when I say HUGE I mean fraction of a second changed to one hour or more!
So I have made an other request to convert it back to latin1.
And here comes the problem. Mere 60k row table, with ONE utf8mb4 column of 64 characters required 10 hours to complete. No, it is not a mistake. TEN hours. And my even bigger problem is that I have other tables that have millions of rows giving me ETA in years from today!
So now, I wonder what my options are because I can't afford having these tables to be read-only for longer than one day time.
I know that MYSQL ALTER creates a copy of a table. It makes sense because this is field size change, so I doubt I have an option to use ALGORITHM=INPLACE.
If I cannot do INPLACE then I cannot use LOCK=NONE option.
Why in the world utf8mb4 -> latin1 conversion could make such a big impact?
Note that the converted column is indexed, and this may be a reason for the impact!
ANY suggestion or a link would be greatly appreciated!
Maybe the solution would be to drop index (to avoid funky multibyte issue in the index conversion,) do fast alter, and then add an index?
Thanks in advance for any serious suggestion and I suspect I may not find much of a help because of the uniqueness of it.
EDIT
jobs | CREATE TABLE `jobs` (
`auto_inc_key` int(11) NOT NULL AUTO_INCREMENT,
`request_entered_timestamp` datetime NOT NULL,
`hash_id` char(64) CHARACTER SET latin1 NOT NULL,
`name` varchar(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`host` char(20) CHARACTER SET latin1 NOT NULL,
`user_id` int(11) NOT NULL,
`start_date` datetime NOT NULL,
`end_date` datetime NOT NULL,
`state` char(12) CHARACTER SET latin1 NOT NULL,
`location` varchar(50) NOT NULL,
`value` int(10) NOT NULL DEFAULT '0',
`aggregation_job_id` char(64) CHARACTER SET latin1 DEFAULT NULL,
`aggregation_job_order` int(11) DEFAULT NULL,
PRIMARY KEY (`auto_inc_key`),
KEY `host` (`host`),
KEY `hash_id` (`hash_id`),
KEY `user_id` (`user_id`,`request_entered_timestamp`),
KEY `request_entered_timestamp_idx` (`request_entered_timestamp`)
) ENGINE=InnoDB AUTO_INCREMENT=9068466 DEFAULT CHARSET=utf8mb4
jobs_archive | CREATE TABLE `jobs_archive` (
`auto_inc_key` int(11) NOT NULL AUTO_INCREMENT,
`request_entered_timestamp` datetime NOT NULL,
`hash_id` char(64) CHARACTER SET latin1 NOT NULL,
`name` varchar(128) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL,
`host` char(20) CHARACTER SET latin1 NOT NULL,
`user_id` int(11) NOT NULL,
`start_date` datetime NOT NULL,
`end_date` datetime NOT NULL,
`state` char(12) CHARACTER SET latin1 NOT NULL,
`value` int(11) NOT NULL DEFAULT '0',
PRIMARY KEY (`auto_inc_key`),
KEY `host` (`host`),
KEY `hash_id` (`hash_id`),
KEY `user_id` (`user_id`,`request_entered_timestamp`)
) ENGINE=InnoDB AUTO_INCREMENT=239432 DEFAULT CHARSET=utf8mb4
(taken from PROCEDURE, but you catch the drift...)
INSERT INTO jobs_archive (SELECT * FROM jobs WHERE (TIMESTAMPDIFF(DAY, request_entered_timestamp, starttime) > days));
I am running MySQL 8.0.17 and trying to add a default value to a column definition, specifically a JSON column.
create table `test` (`id` bigint unsigned not null auto_increment primary key, `name` varchar(255) not null, `notes` json default ('[]')) default character set utf8mb4 collate 'utf8mb4_unicode_ci'
The query executes fine, but when I look at the table structure the default value is listed as "(_utf8mb4'[]')".
This even happens if I set a default value for a VARCHAR field, but enclose the string in parentheses.
I've also tried using the MySQL JSON_ARRAY() function.
create table `test` (`id` bigint unsigned not null auto_increment primary key, `name` varchar(255) not null, `notes` json default (JSON_ARRAY())) default character set utf8mb4 collate 'utf8mb4_unicode_ci'
but this puts the "(json_array())" as a string as the default.
I feel like I'm doing this write based on the documentation. Is this a bug? or am I missing something?
Thanks!
When trying to import database
Error
SQL query:
CREATE TABLE `wp_ihrss_plugin` (
`Ihrss_id` int(11) NOT NULL,
`Ihrss_path` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
`Ihrss_link` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
`Ihrss_target` varchar(50) NOT NULL,
`Ihrss_title` varchar(500) NOT NULL,
`Ihrss_order` int(11) NOT NULL,
`Ihrss_status` varchar(10) NOT NULL,
`Ihrss_type` varchar(100) NOT NULL,
`Ihrss_extra1` varchar(100) NOT NULL,
`Ihrss_extra2` varchar(100) NOT NULL,
`Ihrss_date` datetime NOT NULL DEFAULT '0000-00-00 00:00:00'
) ENGINE=MyISAM DEFAULT CHARSET=utf8
MySQL said: Documentation
#1050 - Table 'wp_ihrss_plugin' already exists
and 5 more tables ; when try to drop one it show that there is another one
One possible approacj to deal with this would be to drop and recreate the object. For instance:
DROP TABLE IF EXISTS `foo`;
CREATE TABLE `foo` ( ... );
There are some duplicate tables present in your database dump.
Check the sql file from which you are trying to import
So i am just a beginner in all this php stuff. I know just the basics, and when i setting up the settings for my new table, I met the problem #1075. Before, i created one, almost similar to this one, and i don't see the differenc. Can you say me where is the problem and explain what is happening?
CREATE TABLE `try`.`testing` ( `id` INT NOT NULL AUTO_INCREMENT , `date` DATE NOT NULL , `text_1` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL , `text_2` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL ) ENGINE = MyISAM;
here is the code of my SQL Preview. I use phpMyAdmin, obviously.
Please, help me.
Thank, you)
Try this
CREATE TABLE `testing` (
`id` INT NOT NULL AUTO_INCREMENT,
`date` DATE NOT NULL,
`text_1` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
`text_2` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
PRIMARY KEY (`id`)
) ENGINE = MYISAM ;
You have to declare your AUTO_INCREMENT field as a primary key or a key. So you have to add PRIMARY KEY (id) or KEY (id) to your CREATE TABLE statement:
CREATE TABLE `try`.`testing` (
`id` INT NOT NULL AUTO_INCREMENT,
`date` DATE NOT NULL ,
`text_1` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL ,
`text_2` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
PRIMARY KEY (`id`) -- as primary key
KEY (`id`) -- or as key
) ENGINE = MyISAM;
Please also check:
https://stackoverflow.com/a/8114994/3647441
https://stackoverflow.com/a/14087703/3647441
For an autoincrement field you should have some sort of index associated with it. eg: primary key which is missing
Try This.
CREATE TABLE `try`.`testing` (
`id` INT NOT NULL AUTO_INCREMENT,
`date` DATE NOT NULL ,
`text_1` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL ,
`text_2` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
KEY (`id`)
) ENGINE = MyISAM;
https://dev.mysql.com/doc/refman/5.6/en/example-auto-increment.html
If so - What must change in this table ?
CREATE TABLE contestants
(
idContestants int(10) unsigned NOT NULL AUTO_INCREMENT,
idEvent int(10) unsigned NOT NULL,
ContestantName varchar(50) DEFAULT NULL,
PRIMARY KEY (idContestants),
UNIQUE KEY Index_UniqueName (idEvent,ContestantName),
)
ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=latin1;
If you mean case sensitive then:
ALTER TABLE `contestants` CHANGE `ContestantName` `ContestantName` VARCHAR( 50 )
CHARACTER SET latin1 COLLATE latin1_bin NULL DEFAULT NULL
If you mean case insensitive then:
ALTER TABLE `contestants` CHANGE `ContestantName` `ContestantName` VARCHAR( 50 )
CHARACTER SET latin1 COLLATE latin1_general_ci NULL DEFAULT NULL
For table level do (for case insensitive):
ALTER TABLE `contestants` DEFAULT CHARACTER SET latin1 COLLATE latin1_general_ci
Note that table level only affects new columns.
For database level do (for case insensitive):
ALTER DATABASE `database_name` CHARACTER SET latin1 COLLATE latin1_general_ci
Note that database level only affect new tables.
Yes, use a case-insensitive collation on the columns involved.
MySQL Manual :: Column Character Set and Collation
This worked for me in Mysql 5.5
ALTER TABLE `contestants` MODIFY
`ContestantName` VARCHAR(50)
CHARACTER SET latin1
COLLATE latin1_bin;