Ok wait — I have a question I see my qualifier and the constraint needs to be equivalent
The qualifier has one fixed string and the second string is — case-insensitive — constraints don’t seem to allow this notion? I see a several suggestions on what is clearly the same, common issue - often usernames have this quality https://stackoverflow.com/questions/637030/lowercase-constraint-sql-server Anyone have insight? > On Nov 22, 2021, at 10:07 AM, Samuel Pelletier <sam...@samkar.com> wrote: > > Jesse, > > So your row have a primary key and some other unique identifier derived other > attributes. > > If the compound key is a combinaison of full attribute values, you cana a > compound unique key in the database. CREATE UNIQUE INDEX ON Table (col1, > col2, ..., coln) > > If it is from partial values, the most reliable way is to add a string column > with the computed key with it's unique constraint. > > If you already have duplicate, you can add a method in the migration to > resolve them before adding the constraint or do it manually... > > Regards, > > Samuel > >> Le 22 nov. 2021 à 09:27, Jesse Tayler <jtay...@oeinc.com> a écrit : >> >> It’s likely just a unique constraint perhaps. >> >> It’s not UIDs or primary keys it’s a unique row type based on a couple >> strings where there should be only one, and that one should last forever. >> >> There’s an API where calls can come in basically at the same time and >> instead of fetching first to see if the object exists, I should likely >> respond to an SQL error rejecting a new row and then fetch and return that >> existing object based on that error condition. >> >> I’d suppose the database is the best place for that policy, but I don’t >> think I’ve implemented constraints quite like that before so I’d need to >> write some sort of Migrations for it if it’s to be reliable in all those >> situations where it might encounter duplicate data…hmmm… >> >> >> >> >>> On Nov 22, 2021, at 8:59 AM, Samuel Pelletier <sam...@samkar.com> wrote: >>> >>> Hi Jesse, >>> >>> Your question may have multiple answers, can you describe the contexts and >>> duplicate sources you fear ? >>> >>> Is the primary key generated by the WO app or it is external (like a GUID) ? >>> >>> Do you have a secondary identifier that should be unique ? >>> >>> Anyway, you should add constraint in to the database if uniqueness is >>> required (this apply to all frameworks in all language) >>> >>> If you use EOF primary key generation, you should not have problems with >>> duplicate keys. If you require high throughput, using UUID primary key or >>> implementing a custom generator will help by saving round trips to the >>> database server. If you insert in batch, it will be also faster than >>> individual inserts. >>> >>> Regards, >>> >>> Samuel >>> >>>> Le 22 nov. 2021 à 08:34, Jesse Tayler via Webobjects-dev >>>> <webobjects-dev@lists.apple.com> a écrit : >>>> >>>> I asked on slack but I figured I’d ping the list >>>> >>>> Who has a good way to ensure a serial EO creation queue when the system >>>> could be hit really fast and you must avoid duplicate entries? >>>> >>>> I’m a bit surprised I don’t recall EOF style solutions for such things and >>>> maybe the Amazon RDS database has a shared connection pattern the apps can >>>> use, I didn’t see anything so I figure this is application level stuff. >>>> >>>> Thoughts? Suggestions? >>>> _______________________________________________ >>>> Do not post admin requests to the list. They will be ignored. >>>> Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) >>>> Help/Unsubscribe/Update your Subscription: >>>> https://lists.apple.com/mailman/options/webobjects-dev/samuel%40samkar.com >>>> >>>> This email sent to sam...@samkar.com >>> >> > _______________________________________________ Do not post admin requests to the list. They will be ignored. Webobjects-dev mailing list (Webobjects-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/webobjects-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
