For some reason, I have to change the default value of one parameter 'param' in a mysql table, I have to set it to NULL by default. I tried to manage it through phpmyadmin and I get this error message :
ALTER TABLE `mytable` CHANGE `param` `param` VARCHAR( 150 ) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT NULL
How can I resolve this ?
You can't set a NOT NULL column to have DEFAULT NULL.
In phpMyAdmin, check the Null? box for the column when editing it.
Related
I am forward engineering a MySQL database from an EER diagram in MySQL workbench, and am being shown the following error on the execution of the statement below:
ERROR: Error 1115: Unknown character set: 'DEFAULT'
CREATE TABLE IF NOT EXISTS `recipes_database_2`.`cleaned_string` (
`id` INT UNSIGNED NOT NULL AUTO_INCREMENT,
`string` VARCHAR(511) CHARACTER SET 'DEFAULT' NOT NULL,
PRIMARY KEY (`id`),
UNIQUE INDEX `string_UNIQUE` (`string` ASC) VISIBLE)
ENGINE = InnoDB
AUTO_INCREMENT = 1
DEFAULT CHARACTER SET = DEFAULT
What can I change to fix this? I want the character set to be the one I set as the default for the database.
Just don't specify the CHARACTER SET at all, then the
database character set and collation are used
as one can read from the documentation.
I want to edit a column in a MySQL table. Right now, it is tinyint with value NULL. I want to change the value to '0'. I tried using this expression:
ALTER TABLE hosts MODIFY COLUMN hide TINYINT NOT NULL DEFAULT 1;
and this
ALTER TABLE hosts MODIFY COLUMN hide TINYINT DEFAULT 1 NOT NULL;
and more variations. But this didn't work for me..
I get this error
EXECUTE FAIL:
ALTER TABLE hosts MODIFY COLUMN hide TINYINT(1) DEFAULT 0 NOT NULL
Message :
Invalid use of NULL value
What's the problem and what is the correct statement?
You cannot alter the table to „not null“ as long as you have data in it with null value.
First set all you data to 0
Update hosts set hide = 0 where hide is null
I want to assign a value as default for a column.
It says that there is a syntax error at line 2 :
SELECT `id` into #idND FROM `xxx` WHERE `name`='John';
ALTER TABLE `xxx2` CHANGE `statut_id` `statut_id` TINYINT(4) NULL DEFAULT #idND;
It works if I set DEFAULT 3 for example. What am I doing wrong please ?
How to set varchar, text, int default to NULL in Mysql?
I have a table, some columns are optional for the user to fill.
I want to set the default to NULL if the user didn't fill any thing.
I try to do it in PHPMyAdmin, but I got error #1067 - Invalid default value
Make sure that the option Null for the column be checked.
I am using migration toolkit for the migration but i am getting these errors in the process of migration
Incorrect table definition; there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause
Incorrect string value: '\xEF\xBF\xBDs d...' for column 'MESSAGE' at row 5
0 row(s) transferred.
For the fixing the first error i got something here http://terrencemiao.com/Webmail/msg00949.html
but i am not getting the second error what it is and why is it there how to fix it also suggest me some better ideas for fixing the first one if there any apart from what mentioned in the link
USE `MyDB`
Creating tables ...
Creating table MyTable...
DROP TABLE IF EXISTS `MyTable`
Creating table MyTable ...
SET NAMES UTF8;
CREATE TABLE `MyTable` (
`PrimaryKey` INT(10) NOT NULL AUTO_INCREMENT,
`FK_QUESTION_ID` INT(10) NOT NULL,
`ANSWER` LONGTEXT CHARACTER SET utf8 COLLATE utf8_general_ci NULL
PRIMARY KEY (`PK_ID`)
)
ENGINE = INNODB
i am getting error for answer column
*Incorrect table definition; there can be only one TIMESTAMP column with CURRENT_TIMESTAMP in DEFAULT or ON UPDATE clause*
This is right, you should not create more then one such fields.
Incorrect string value: '\xEF\xBF\xBDs d...' for column 'MESSAGE' at row 5 0 row(s) transferred.
Possible encoding error, try to run 'SET NAMES UTF8;' before inserting data
Try this statement,
CREATE TABLE `MyTable` (
PK_ID INT(11) NOT NULL AUTO_INCREMENT,
FK_QUESTION_ID INT(11) NOT NULL,
ANSWER LONGTEXT CHARACTER SET utf8 COLLATE utf8_general_ci NULL,
PRIMARY KEY (`PK_ID`)
)
ENGINE = INNODB;
You missed a comma and it was wrong field name. Be careful with migration toolkit. Check generated field types, for example if you do not need 4GB text values, you could use simple VARCHAR instead of LONGTEXT.