No, I can not compute inside forEachRow. ForEachRow is now universal, can be applied to any table. If I modify SELECT inside it to fit specific purpose, forEachRow will use universality.
Roman ________________________________________ From: sqlite-users [sqlite-users-boun...@mailinglists.sqlite.org] on behalf of Richard Damon [rich...@damon-family.org] Sent: Friday, January 26, 2018 6:26 PM To: sqlite-users@mailinglists.sqlite.org Subject: Re: [sqlite] primary key in another column One question I have, couldn't you just omit the fileName column from the able, and compute it in the select query that is getting the data? On 1/26/18 6:03 PM, Roman Fleysher wrote: > My implementation of "for Each row" requires all columns to be populated. It > is a dumb thing: > > forEachRow commandToBeExecuted itsArgumentsWhichReferToColumns > > The files are images. Example: > > forEachRow addImages outputColumn column1 column2 > > ForEachRow will loop over the rows (in parallel batches if it can) and apply > the command given to it with its arguments. Image processing is then a > sequence of these "forEach" commands. > > > Roman > > On 1/26/2018 5:47 PM, Roman Fleysher wrote: >> 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. > I'm still not sure I understand, but: while you are building out this manager > table, can't you leave fileName column blank, and then right before > processing, run UPDATE A SET fileName='prefix_'||ID; on it? > -- > Igor Tandetnik -- Richard Damon _______________________________________________ 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
