one()

Retrieves one entity from the table.

This is similar to first() in the sense that it retrieves only the first matching entity, but:

• it throws an exception if no entity was found
• it throws an exception if more than one entity matched the filter

This makes it perfect for retrieving entities by their primary id, which are unique by default.

let alice: User;
// Retrieve directly by id
alice = await one(userTable, "alice-uuid");
// Retrieve with filter (equivalent to the line above!)
alice = await one(userTable, {
  where: {
    id: "alice-uuid"
  }
});

Retrieve by primary id

In case an id is given as the second parameter, one() will return either the entity with a matching primary id, or throw as detailed above.

const alice = await one(userTable, "alice-uuid");

Retrieve by filter

If the second parameter is a filter, one() returns the item that matches the filter, or throws if no or more than one item is available.

const alice = await one(userTable, {
  where: {
    id: "alice-uuid"
  }
});