How to download a table data from Google BigQuery ?

Bigquery WebUI allows you to export results to csv files. However if your table has millions of rows, this method may not be efficient. Alternatively, you can install the google  Cloud SDK (Software development kit) that helps you to extract the table data into csv files and then ftp the files back to your laptop

1. Install the Google Cloud SDK
   Download and install the SDK version for you operating system
2. Authenticate and Initialize your account
   From the command prompt, run 
   gcloud init
   and 
   gcloud auth login
   to initialize your account. This is a one time activity
3. Create a GCP Storage bucket to store the exported data
4. Run the following command to export your table to the storage bucket that we just created
   

   bq extract my_dataset.my_table gs://mybucket/myfilename.csv
   
   Replace the table name and bucket names with yours

5. Run the below command to download the files from the cloud storage buckets to your laptop
   

   gsutil -m cp -r 'gs://<bucket>/prefix_*' .

6. once the files are downloaded. Remember to cleanup your cloud storage
   gsutil rm gs://<bucket>/prefix_*

You are all set !

nVector

posted on 11 May 20