Sounds like you are using Postgres? You can use the syntax “not valid” when you create a constraint to stop the bleeding immediately. It will then only check for new and modified records allowing the bad rows to co-exist. When you get around to it, you can remove the duplicates.
If it’s another database, they likely have something similar. > On Nov 22, 2021, at 10:18 AM, Jesse Tayler <jtay...@oeinc.com> wrote: > > It’s not a compound key so much as just policy — it’s a handle for social > service and so there should just be one row with that value and don’t need to > tie into the key > > I guess I can create a unique index just for that one attribute and it would > presumedly return an error upon save. I should re-write the EO to handle that > error raise and respond by returning the existing object… > > I guess that is not hard to figure if that approach sounds sane. > > I do have dups and I’d guess the constraint will simply fail if the database > has any dups in it. > > I guess writing a migration to handle / remove dups is not practical so I’d > likely remove them by hand, then add the constraint in a migration update > that would gently fail until there are no more dups… > > > >> 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
