An incomplete attempt at "SELECT without FROM" in Drizzle

select-without-from.ts

import { sql, Subquery, WithSubquery, type SQL, type SQLWrapper } from 'drizzle-orm'
import type { SelectResultField } from 'drizzle-orm/query-builders/select.types'

type SelectResultFields<TSelectedFields extends Record<string, any>> = {
  [K in keyof TSelectedFields]: TSelectedFields[K] extends SQLWrapper
    ? SelectResultField<TSelectedFields[K]>
    : SQL<TSelectedFields[K]>
}

export function select<TAlias extends string, const TSelectedFields extends Record<string, any>>(
  alias: TAlias,
  fields: TSelectedFields
) {
  return new WithSubquery(
    sql<SelectResultFields<TSelectedFields>>`SELECT ${sql.join(
      Object.entries(fields).map(([key, value]) => {
        if (!('_' in value) || 'alias' in value._) {
          return sql`${value}`
        }
        return sql`${value} AS ${key}`
      }),
      sql`, `
    )}`,
    {},
    '',
  )
}

// WITH date_range AS (
//   SELECT generate_series('2023-01-01'::date, '2023-12-31'::date, '1 MONTH'::interval)::date AS date
// )

// import { db } from '~/db/client.ts'

// db.$with('date_range').as(() =>
//   select('date_range', {
//     date: sql`generate_series('2023-01-01'::date, '2023-12-31'::date, '1 MONTH'::interval)::date`,
//   })
// )