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

I am trying to add and modify SQL queries so that I'm using windowed functions, string manipulations and unions.

What did you learn from the changes you have made?

I learned that windowed functions and unions are quite powerful, especially in ranking cases.

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

I thought about using dense rank but i decided to use row_number instead because there might be unique cases of one customer visiting on different days.

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

Not too much, but the union was a bit challenging so I had try it multiple times.

How were these changes tested?

Primarily through DB browser for SQLite.

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

n/a

Checklist

• I can confirm that my changes are working as intended