default a column with empty string

问题

Is there a way, via a SQL statement, to ensure a column's default value is an empty string '' instead of NULL?

回答1:

Yes - use a DEFAULT constraint:

DROP TABLE IF EXISTS `example`.`test`;
CREATE TABLE  `example`.`test` (
  `string_test` varchar(45) NOT NULL DEFAULT ''
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

来源：https://stackoverflow.com/questions/3357953/default-a-column-with-empty-string