Alter SQL table – allow NULL column value

Initially, the table “MyTable” has been defined in the following way:

CREATE TABLE IF NOT EXISTS `MyTable` (
  `Col1` smallint(6) NOT NULL AUTO_INCREMENT,
  `Col2` smallint(6) DEFAULT NULL,
  `Col3` varchar(20) NOT NULL,
);

​x
 
CREATE TABLE IF NOT EXISTS `MyTable` (  `Col1` smallint(6) NOT NULL AUTO_INCREMENT,  `Col2` smallint(6) DEFAULT NULL,  `Col3` varchar(20) NOT NULL,);​

How to update it in such a way that the column “Col 3” would be allowed to be NULL?

Answer

The following MySQL statement should modify your column to accept NULLs.

ALTER TABLE `MyTable`
ALTER COLUMN `Col3` varchar(20) DEFAULT NULL

 
ALTER TABLE `MyTable`ALTER COLUMN `Col3` varchar(20) DEFAULT NULL​

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Answer