Igor, you are absolutely right. But....
I will use this table as a manager. There will be multiple columns holding various file names. The names can be random, but I want humans to be able to easily inspect. After table is filled, an operation "for each row" will get files in some columns and produce files in other columns. This is done outside of SQLite. "For each row" will process several rows in parallel because they are independent. Some operations might fail and will be recored in the proper columns. After all the work is done, the manager table is discarded. "For each row" is equivalent to SELECT, but it operates on the files themselves. This can be implemented within SQLIte by loading extension. I investigated this route (and even asked questions on this list) and eventually concluded that it is better to do outside because of the way parallel execution is done (sometimes sent to a compute cluster grid engine for queueing.) This makes no sense from the database point of view: No reason to hold redundant data with such a simple algorithm to generate it. Roman ________________________________________ From: sqlite-users [sqlite-users-boun...@mailinglists.sqlite.org] on behalf of Igor Tandetnik [i...@tandetnik.org] Sent: Friday, January 26, 2018 5:33 PM To: sqlite-users@mailinglists.sqlite.org Subject: Re: [sqlite] primary key in another column On 1/26/2018 4:43 PM, Roman Fleysher wrote: > I would like to use primary key as a way to create unique column entry: > > CREATE TABLE A( id INTEGER PRIMARY KEY, fileName TEXT NOT NULL) > > such that file name is always prefix followed by the ID for the content to be: > > ID fileName > > 1 prefix_1 > 2 prefix_2 Why do you want to store redundant data? What's the actual problem this is supposed to help you solve? As stated, this looks like an XY problem ( http://xyproblem.info/ ) -- Igor Tandetnik _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
