alter table: char vs varchar

[slava_php]

hi,
i have mysql and i was modifying column type from var(20) to varchar(64) and as a result, it changed most columns to varchar type in several tables in this database (although it kept the right char number). no other databases were affected.

the statement was:

alter table usertable modify userid varchar(64) not null;

what happened?

thanks,
steve

[sfullman]

I just learned about this today actually, for a table if you have any varchar fields, they will all be varchar. I suppose if you change them all simultaneously to char again it would revert, but change one and you change them all

Sam Fullman

[[deleted]]

Indeed, mysql in it's infinate stupidity changes all CHAR columns in a table to VARCHAR if one colum in that table is defined as/changed to VARCHAR.