How do I drop 'NOT NULL' from a column in MySQL?

mysql alter-table
Will picture Will · Jun 8, 2010 · Viewed 29.4k times · Source

A show create table command shows the following:

'columnA' varchar(6) NOT NULL DEFAULT '';

How do I modify that column so that the not null is removed? I need it to be:

'columnA' varchar(6) DEFAULT NULL;

I thought the following would work, but it has no effect:

ALTER TABLE tbl_name MODIFY columnA varchar(6) DEFAULT NULL;

Answer

Eric Petroelje picture Eric Petroelje · Jun 8, 2010

Try this instead:

ALTER TABLE tbl_name MODIFY columnA varchar(6) NULL DEFAULT NULL;

Related questions

How to delete a column from a table in MySQL

Given the table created using: CREATE TABLE tbl_Country ( CountryId INT NOT NULL AUTO_INCREMENT, IsDeleted bit, PRIMARY KEY (CountryId) ) How can I delete the column IsDeleted?

Read More
Error renaming a column in MySQL

How do I rename a column in table xyz? The columns are: Manufacurerid, name, status, AI, PK, int I want to rename to manufacturerid I tried using PHPMyAdmin panel, but I get this error: MySQL said: Documentation #1025 - Error on …

Read More
Alter a MySQL column to be AUTO_INCREMENT

I’m trying to modify a table to make its primary key column AUTO_INCREMENT after the fact. I have tried the following SQL, but got a syntax error notification. ALTER TABLE document ALTER COLUMN document_id AUTO_INCREMENT Am …

Read More