How do I modify a MySQL column to allow NULL?

MySQL 5.0.45

What is the syntax to alter a table to allow a column to be null, alternately what's wrong with this:

ALTER mytable MODIFY mycolumn varchar(255) null;

I interpreted the manual as just run the above and it would recreate the column, this time allowing null. The server is telling me I have syntactical errors. I just don't see them.

 Answers

You want the following:

ALTER TABLE mytable MODIFY mycolumn VARCHAR(255);

Columns are nullable by default. As long as the column is not declared UNIQUE or NOT NULL, there shouldn't be any problems.

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My solution:

ALTER TABLE table_name CHANGE column_name column_name type DEFAULT NULL

For example:

ALTER TABLE SCHEDULE CHANGE date date DATETIME DEFAULT NULL;

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Use: ALTER TABLE mytable MODIFY mycolumn VARCHAR(255);