Is a master table with only one column necessary in this mysql example?

I have a mysql DB with a table that holds version information for multiple other tables. In order to link to the same family of versions I have a version_master table that holds a primary key to the family of versions that the link refers to. I was wondering if there was a more elegant solution without the need for a version_master table.

CREATE TABLE IF NOT EXISTS `version` (
`version_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`version_master_id` int(10) unsigned NOT NULL,
`major` int(10) unsigned NOT NULL DEFAULT '0',
`minor` int(10) unsigned NOT NULL DEFAULT '0',
`patch` int(10) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`version_id`));

CREATE TABLE IF NOT EXISTS `version_master` (
`version_master_id开发者_高级运维` INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY);

CREATE TABLE IF NOT EXISTS `needs_versions` (
`needs_versions_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`date_created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
`name` varchar(128) COLLATE utf8_unicode_ci NOT NULL,
`description` text COLLATE utf8_unicode_ci NOT NULL,
`version_master_id` int(10) unsigned NOT NULL,
PRIMARY KEY (`needs_versions_id`));

In this example you can certainly eliminate the version_master table and use the combination of version_id and version_master_id fields as an index. I think you can just drop it, because nothing seem to refer to it with a foreign key.

However, having version_master would be a good idea if you had additional information associated with each family of versions.

Also, you are trying to make a primary key out of the undefined column offer_type_id. It is not clear whether you can logically merge needs_versions with version_master or not. The name itself is not very descriptive. I would recommend not to use verbs in table names.

The other common way to do this is to use SEQUENCEs.

But MySQL does not seem to support them, at least the MySQL manual contains a section on how to simulate sequences using a one row, one column table:

Create a table to hold the sequence counter and initialize it:

CREATE TABLE sequence (id INT NOT NULL);
INSERT INTO sequence VALUES (0);

Use the table to generate sequence numbers like this:

UPDATE sequence SET id=LAST_INSERT_ID(id+1);
SELECT LAST_INSERT_ID();