Convex Ents: when defining m:m relationships, must the junction table have its own defineEnt()
when defining many to many relationships using Convex Ents, must the junction table have its own defineEnt()?
- If I don't give the junction table its own defineEnt, then I get an error in npx convex dev like:
Argument of type 'myJunctionTable"' is not assignable to parameter of type 'TableNamesInDataModel<EntDataModelFromSchema<SchemaDefinition<{
If I do provide a defineEnt() for the junction table, then I will get the error:
400 Bad Request: FieldsNotUniqueWithinIndex: Hit an error while evaluating your schema:
In table "directMessageChannelMembers": In index "directMessageChannelId": Duplicate field "directMessageChannelId". Index fields must be unique within an index.
If I don't specify the field name in the edges() function, then Convex Ents will use my table name (which is in plural form) to generate the field names. That may be a separate issue, reported here:
https://discord.com/channels/1019350475847499849/1270846055017353328
- Also, if I need to add more columns to the junction table beyond the foreign keys, then it seems I need to give the junction table its own defineEnt()
1 Reply
The documentation seems to imply that you don't need to create a defineEnt(), but I am blocked by that error without a separate defineEnt().
Where is an example of a many-to-many relationship in an app?
The saas-starter does not seem have a happy path example of a many-to-many relationship.
It has:
1) an explicit defineEnt() for
members, which does not seem to be a bona fide many-to-many. It is effectively a junction table, but it seems made of multiple one-to-many relationships.
2) There might be a many-to-many relationship between permissions and roles, but there is some additional logic around vPermissions that makes this relationship hard to understand
Interesting, I
1) cleared the directMessageChannelMembers table,
2) removed the field option from my edges() functions.
3) explicitly gave the junction table a defineEnt()
and npx convex dev no longer shows the error:
In table "directMessageChannelMembers": In index "directMessageChannelId": Duplicate field "directMessageChannelId". Index fields must be unique within an index.
npx convex dev moved on to a different issue.
Maybe there is an index conflict if you already have a pre-existing Convex project using Vanilla Convex, and then you're converting schema.ts to use Convex Ents.
To future readers, I was able to get the many-to-many to work by doing two things:
1) providing the junction table its own defineEnt() in schema.ts
2) paying close attention to this error message.
This error message is about my pre-existing data created by my vanilla Convex setup, not about my new Ents setup in schema.ts. When I cleared the table, Convex probably deleted the pre-existing index. Afterwards, there was no longer a duplicate index.