Webhook Relay
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GCP BigQuery

BigQuery is one of the most popular data warehouses in the world. Webhook Relay functions allow directly inserting data into them.
Webhook Relay to BigQuery
Prerequisites:
Webhook Relay provides a helper package bigquery that can stream writes into Google Cloud BigQuery. To start ingesting data from webhooks straight into your BigQuery table, create a new Function and just import ‘bigquery’ package:
-- Import BigQuery helper package
local bigquery = require('bigquery')
A new tab should appear that will ask you to set up credentials:
Configure GCP credentials
Go to that tab and it will ask you to:
  1. 1.
    Create new service accounts with BigQuery Editor permissions
  2. 2.
    Download the JSON file. Once you have the JSON file
  3. 3.
    Copy & paste contents into the form and click save.

Streaming data to GCP BigQuery

-- Import BigQuery helper package
local bigquery = require('bigquery')
local json = require("json")
-- Parsing payload
local rowData, err = json.decode(r.RequestBody)
if err then error(err) end
-- Initializing BigQuery client
err = bigquery.initialize('your-project-id', 'dataset-id', 'table-id')
if err then error(err) end
-- Receiving payload:
-- {
-- "hub_user_id": "user-id-here",
-- "category": "signup",
-- "action": "click",
-- "label": "github auth"
-- }
-- Insert row:
err = bigquery.insert(rowData)
if err then error(err) end

Check if record exists

A simple query to check whether a row exists by matching a column with a value:
bigquery = require('bigquery')
err = bigquery.initialize('your-project-id', 'dataset-id', 'table-id')
if err then error(err) end
local exists, err = bigquery.record_exists('name', 'john')
if err then error(err) end
if exists then
-- OK
else
error('Record not found')
end

Execute any command

To execute any SQL command on your table:
bigquery = require('bigquery')
err = bigquery.initialize('your-project-id', 'dataset-id', 'table-id')
if err then error(err) end
-- Delete old records of the matching category. Method 'exec' can take an arbitrary
-- number of arguments, depending on how many ? you have in your query.
err = bigquery.exec('DELETE dataset-id.table-id WHERE category = ? AND country = ?', 'movies', 'US')
if err then error(err) end

BigQuery package API reference

At the moment there’s a single client method that bigquery package exposes:
Method name
Parameter Type
Description
insert(rowData)
Table
A table [key]value that represents a row data.
record_exists(column, value)
String, String
Checks if a row with the matching column exists

Limitations

Currently our package doesn’t support nested objects. That means that a table with a JSON structure such as:
{
"hub_user_id": "user-id-here",
"category": "signup",
"action": "click",
"label": "github auth",
"nested_data": {
"location": "GB",
"date": "2020-05-10"
}
}
will not be successfully inserted. Therefore, flatten the structure in the function before inserting it.

Troubleshooting

Few things to note:
  • Ensure that project ID, dataset ID and table ID are there.
  • BigQuery table schema is defined by the user. You don’t have to write all the fields (most of the can be nullable) but if you try to write a field that doesn’t exist, BigQuery will refuse to write.