Query to Generate Fake Dataset in Google BigQuery

fake_data.sql

-- https://medium.com/google-cloud/yet-another-way-to-generate-fake-datasets-in-bigquery-93ee87c1008f

CREATE TEMP FUNCTION entity(seed INT64)
RETURNS STRUCT<transaction_id String, user_id Integer, transaction_date String, ledger_type String, points Integer, partner String, remarks String, country String>
LANGUAGE js 
AS """
  
  var t = {};
  var items = [100,150,200,250,300,350,400]
  var countries = ["sg", "id"]
  var remark_list = ["completed article","completed survey","redeemed points"]
  var types = ["redeemed", "earned"]
  function makeid(length) {
        var result           = '';
        var characters       = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
        var charactersLength = characters.length;
        for ( var i = 0; i < length; i++ ) {
        result += characters.charAt(Math.floor(Math.random() * 
    charactersLength));
    }
    return result;
    }
  function randomDate(start, end) {
    return new Date(start.getTime() + Math.random() * (end.getTime() - start.getTime()));
  }
  t.transaction_id = makeid(64)
  t.user_id = Math.floor(Math.random() * 1000);
  t.transaction_date = moment(randomDate(new Date(2021, 0, 1), new Date())).format('YYYY-MM-DD HH:MM:SS');
  t.ledger_type = types[Math.floor(Math.random()*types.length)];
  t.points = items[Math.floor(Math.random()*items.length)]
  t.partner = "internal"
  
  t.remarks = remark_list[Math.floor(Math.random()*remark_list.length)]
  t.country = countries[Math.floor(Math.random()*countries.length)]
  return t;
"""
OPTIONS (
    library=["gs://<bucket-name>/moment.js"]
);
-- SELECT entity().*
CREATE OR REPLACE TABLE dataset.ledger AS (
  SELECT row_num as id, entity(row_num).*
  FROM dataset.row_seq
  where row_num <= 150000000
);