showing error [symbol.iterator()] in ts generics in knex query

Question

const [user]: T = await db("users").insert(data).returning("*");
// error:Type 'T' must have a '[Symbol.iterator]()' method that returns an iterator.

My knex query typescript giving me error when i tried brackets in knex query to return single object from array.Can someone help me understand to why it is showing me this error even when i passed specific generic type and "user" variable is storing a single object as specified by type.Is there any go through from it, I also tried with .first() instead of square brackets but it shows a different error then.

const user: T = await db("users").insert(data).first().returning("*");

//error: Type 'any[]' is not assignable to type 'T'.
//  'T' could be instantiated with an arbitrary type which could be unrelated to 'any[]'.

Answer 1

Remove the .first(). Not sure it works well together with the returning(). Since it will be returning an array in ALL cases, you may as well do T[]. It should accept it.

const user: T[] = await db("users").insert(data).returning("*");

Good luck

Answer 2

Simply do:

const user: T = await db("users").select("*").first();

.returning() is for inserts, updates, and deletes, not selects.