README.md

BigQuery Table Comparison Flask API

Python-based utility to automate the comparison of two BigQuery tables, exposed as a Flask API. Identifies mismatched data, schema discrepancies, added/deleted rows, and validates table existence and key uniqueness.

Key Features

• Identifies mismatches in both data and schema.
• Detects added, deleted, and modified rows based on key columns.
• Supports comparison of specific columns.
• Provides a user-friendly API interface.

Prerequisites

• Python 3.x
• Flask
• Google Cloud BigQuery Python client library (google-cloud-bigquery)
• Access to a Google Cloud Project with BigQuery API enabled

Installation - change to the correct python version

bash build_venv.sh 

Usage

1. Set Environment Variables:

• GOOGLE_APPLICATION_CREDENTIALS: Path to your Google Cloud service account credentials JSON file.

2. Start the Flask application:

export FLASK_APP=app.py flask run

3. Send a POST request to the /table-diff endpoint: (see run_example.py)

{
    "project_id": "your-project-id",
    "dataset_id1": "dataset1",
    "dataset_id2": "dataset2",
    "table1": "table1_name",
    "table2": "table2_name",
    "key_columns": ["key_column1", "key_column2"],
    "compare_columns": ["column1", "column2"]
}

To Do

• add option to ouput to a bigquery table