Drizzle Team•12mo ago

How to use the Batch API?

Hi, I am using Turso and have an array of people I need to insert into my database. I've tried via db.insert(people).values(peopleArray) but get an error about too many variables or something so then I looked into the batch API, but this doesnt work either:

db.batch(peopleArray.map(p => db.insert(people).values(p))

db.batch(peopleArray.map(p => db.insert(people).values(p))

But I can do something like this which works for a single entry?

const person = { id: 1, name: "Tester" }
const ins = db.insert(people).values(person)
db.batch([ins])

const person = { id: 1, name: "Tester" }
const ins = db.insert(people).values(person)
db.batch([ins])

So why can't I do something similar with an array?

Solution:

You could have a helper like this: ```ts function isTuple<T extends any[]>(array: T): T is [T, ...T[]] { return array.length > 0; }...

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3 Replies

Angelelz•12mo ago

db.batch accepts a tuple with at least 1 item. The shape is [T, ...T[]] Typescript is complaining because it can't statically verify that there's at least one item in that array

Solution

Angelelz•12mo ago

You could have a helper like this:

function isTuple<T extends any[]>(array: T): T is [T, ...T[]] {
   return array.length > 0;
}

function isTuple<T extends any[]>(array: T): T is [T, ...T[]] {
   return array.length > 0;
}

With that you can please the compiler

BiffBaffBoffOP•12mo ago

Hiya, thanks for the reply but that still doesnt work:

function isTuple<T>(array: T[]): array is [T, ...T[]] {
  return array.length > 0
}

function isTuple<T>(array: T[]): array is [T, ...T[]] {
  return array.length > 0
}

Further down:

if (isTuple(peopleArray)) {
  const ins = peopleArray.map((p) => db.insert(people).values(p))
  await db.batch(ins)
}

if (isTuple(peopleArray)) {
  const ins = peopleArray.map((p) => db.insert(people).values(p))
  await db.batch(ins)
}

Error: Source provides no match for required element at position 0 in target Ah nvm, sorry it does work, needed to do this:

    if (isTuple(ins)) {
      await db.batch(ins)
    }

    if (isTuple(ins)) {
      await db.batch(ins)
    }

Thanks again for your help

Gaming

Programming

How to use the Batch API?