docs: def get_zcta_ids(state=None):
      """ Get ids of all supported ZCTAs, optionally by state.
  
      Parameters
      ----------
      state : str, optional
          Select zipcodes only from this state or territory, given as 2-letter
          abbreviation (e.g., ``'CA'``, ``'PR'``).
  
      Returns
      -------
      results : list of str
          List of all supported selected ZCTA IDs.
      """
      conn = metadata_db_connection_proxy.get_connection()
      cur = conn.cursor()
  
      if state is None:
          cur.execute(
              """
            select zcta_id from zcta_metadata
          """
          )
      else:
          cur.execute(
              """
            select zcta_id from zcta_metadata where state = ?
          """,
              (state,),
          )
      return [row[0] for row in cur.fetchall()]