text: -- Import v1 MapSwipe data from csv to
  -- the v2 MapSwipe database.
  -- Make sure the v1 data is v2 conform
  -- otherwise default to NULL value.
  
  CREATE TEMP TABLE v1_users (
      user_id varchar,
      username varchar,
      created timestamp DEFAULT NULL
  );
  
  -- Has to be in one line otherwise syntax error
  \copy v1_users(user_id, username) FROM users.csv WITH (FORMAT CSV, DELIMITER ',', HEADER TRUE);
  
  -- Insert or update data of temp table to the permant table.
  INSERT INTO
    users(
      user_id,
      username
    )
  SELECT
    user_id,
    username
  FROM
    v1_users
  ON CONFLICT (user_id) DO NOTHING;
  