Defined patern for mysql table primary key

is there anyway to create lets say pattern for primar开发者_运维问答y key i.e. for table products such pattern would by p-1,p-2... p-n etc.

Thanks

Well, you can manually create and enforce that pattern into your application (or using triggers). A primary key just needs to be unique to work.

But I don't recommend it. In your sample, seems P-1 have a business meaning. And, if it belongs to your business realm, it can be changed. While most database have a UPDATE CASCADE equivalent, it doesn't change basic reason you shouldn't use that as key: it's information, not data.

I suggest you to create a field named ProductCode char(10) NOT NULL UNIQUE and maybe to fill it with P-00000001, P-00000002, and so on. Maybe you do prefer to use a varchar: this doesn't matter, as it must fulfill your business requirement. Create an Id INTEGER AUTO_INCREMENT PRIMARY KEY field to use as primary key, as it doesn't never needs to be changed.