Drizzle Team•16mo ago

implementing generics with crud and classes

I am trying to implement a base class, that could be overwritten/extended with the help of generics, but I am running into an issue with my create function, where I kinda get blown into generics hell the more I look at the type error. If anyone could help or just tell me that creating something like this is impossible please let me know haha. The issue I'm running into is in the create method where the values I'm passing in aren't happy with what it expects even though the Insert type is the inferred Insert of that specific table. Which doesn't make sense because update works as expected

import { Database, InjectDrizzle } from "@modules/drizzle";
import { Injectable } from "@nestjs/common";
import { PgTableWithColumns, TableConfig } from "drizzle-orm/pg-core";
import { eq } from "drizzle-orm";

@Injectable()
export abstract class CrudService<
  Table extends PgTableWithColumns<TableConfig>,
  Insert = Table["$inferInsert"],
  Update = Partial<Table["$inferInsert"]>,
> {
  constructor(
    private readonly table: Table,
    protected readonly model: string,
    @InjectDrizzle() private readonly db: Database,
  ) {}

  create<DTO extends Insert>(create: Insert | DTO) {
    this.db.insert<Table>(this.table).values(create);
  }

  update(id: string, update: Update) {
    this.db.update<Table>(this.table).set(update).where(eq(this.table.id, id));
  }
}

import { Database, InjectDrizzle } from "@modules/drizzle";
import { Injectable } from "@nestjs/common";
import { PgTableWithColumns, TableConfig } from "drizzle-orm/pg-core";
import { eq } from "drizzle-orm";

@Injectable()
export abstract class CrudService<
  Table extends PgTableWithColumns<TableConfig>,
  Insert = Table["$inferInsert"],
  Update = Partial<Table["$inferInsert"]>,
> {
  constructor(
    private readonly table: Table,
    protected readonly model: string,
    @InjectDrizzle() private readonly db: Database,
  ) {}

  create<DTO extends Insert>(create: Insert | DTO) {
    this.db.insert<Table>(this.table).values(create);
  }

  update(id: string, update: Update) {
    this.db.update<Table>(this.table).set(update).where(eq(this.table.id, id));
  }
}

Any help/suggestions will be greatly appreciated. Thank you in advance

1 Reply

NinjaBunnyOP•16mo ago

the type error is very long, if it's required I'll send the entire type haha found this by just scrolling down a bit https://discord.com/channels/1043890932593987624/1147439990683488268

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implementing generics with crud and classes