What changes are you trying to make? (e.g. Adding or removing code, refactoring existing code, adding reports)

Completed Assignment 2, which includes:

• SQL queries covering COALESCE, window functions, string manipulations, UNION, CROSS JOIN, INSERT, DELETE, and UPDATE.
• Logical data model diagrams for a bookstore, including shifts and customer address architectures (Type 1 and Type 2 Slowly Changing Dimensions).

What did you learn from the changes you have made?

I improved my understanding of advanced SQL techniques, especially window functions, COALESCE, and managing slowly changing dimensions (Type 1 and Type 2).

• I practiced applying SQL concepts in realistic business scenarios, including data cleaning, data modeling, and historical tracking.

Was there another approach you were thinking about making? If so, what approach(es) were you thinking of?

• I explored different options for handling customer address changes but followed the assignment instructions to implement Type 1 and Type 2 approaches.

Were there any challenges? If so, what issue(s) did you face? How did you overcome it?

I encountered difficulties with the UPDATE query that required fetching the latest quantity per product. Initially, I referenced a non-existing column, but after reviewing the schema, I used the market_date column to determine the most recent record, which resolved the issue.

How were these changes tested?

• I ran all SQL queries in DB browser for SQL lite, verified outputs with SELECT statements, and checked that the updates (e.g., current_quantity) reflected the expected values.

A reference to a related issue in your repository (if applicable)

Checklist

• [x ] I can confirm that my changes are working as intended