Moving data

Table of contents

1. Introduction
2. Implementation
3. How to run

Introduction

We are provided with a zip file containing JSON documents listing orders. We have to put these JSON documents in a PostgreSQL database.

Implementation

I used the Python library psycopg2 to interface with PostgreSQL.

Here is the logic of the main() function:

open zip file
for each JSON document
    convert document to Python objects (list of dictionaries)
    for each "order" element in the list of dictionaries
        collect list of "line_items"
        insert "order" in a PostgreSQL "orders" table
        for each item in the "line_items" list
            insert item in the "items" table

To prevent SQL injection with dynamically generated SQL executable strings, I use either the sql.Identifier for table names or direct string composition in the cursor.execute() function argument.

How to run

Place input zip files in the input folder at the root of the repository, and execute run.sh.