Select One and Only One or Throw

[JadenSWang]

Is there anything in drizzle-orm's toolkit which allows you to query and select for only one item and throw an error if multiple or zero results are returned? I'm in the middle of migrating from a strange mix of stored procedures and quite often do I find myself checking if result > 1 and not 0.

I imagine this could be done even quicker with the use of UNIQUE fields.

[0xPT]

Bump

[Angelelz]

Drizzle doesn't have this feature just yet but a workaround would look something like this:

// Define this helper somewhere in your codebase:
const takeUniqueOrThrow = <T extends any[]>(values: T): T[number] => {
  if (values.lenght !== 1) throw new Error("Found non unique or inexistent value")
  return values[0]!
}

// Use it in a query as follows:
const user = await db.select().from(users).where(eq(users.id, userId)).then(takeUniqueOrThrow);
//     ^? const user: { id: string; name: string; ... }

[Angelelz]

No, those are equivalent.

[capaj]

@Angelelz please include this or similar helper in drizzle

[Warchant]

You can also customize an error message

export const takeUniqueOrThrow = (message: string) => {
    return <T>(values: T[]): T => {
        if (values.length !== 1)
            throw new Error(`Found non unique or inexistent value: ${message}`);
        return values[0]!;
    };
}

[Tigatok]

@Angelelz not meaning to resurrect this thread, is the comment from Vijay technically better because the T extends any throws a linting error if expecting any?

Thanks in advance,

[Angelelz]

@Angelelz not meaning to resurrect this thread, is the comment from Vijay technically better because the T extends any throws a linting error if expecting any?

I think it's a matter of taste. I can't think of why it would be better. Both are constraining the input to an array of any. Maybe mine wouldn't accept an array of never? Not sure if this answers your question