Re: Regarding "[Warning] InnoDB: Cannot add field"

[Peter Brawley]

Please pardon my bluntness---the table design is a recipe for performance disaster, so I'm relieved MySQL5.7 refuses to go along with it.

So does MySQL 8.0. As a rule of thumb, more than a hundred columns/table indicates serious design issues till proved otherwise.

May I suggest an alternative along these lines ...

CREATE TABLE `testcase` (
`id` bigint unsigned primary key auto_increment,
`phnareacode` varchar(32) DEFAULT NULL COMMENT '_extra',
`devid` bigint unsigned DEFAULT NULL COMMENT '_extra',
`second_id`int unsigned NOT NULL COMMENT '_extra',
);

CREATE TABLE testcase_details(
id bigint unsigned primary key auto_increment,
parentid bigint unsigned,
foreign key(parentid) references testcase(id)
on delete cascade on update cascade,
idx enum( col0 ... col233)
text text
);