Joon Han | Digital Diagnostics

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SQL Analysis

A collection of case studies using SQL to clean data, join tables, segment patterns, and answer business questions with structured logic.

These projects show how raw datasets are transformed into analysis-ready outputs through querying, aggregation, comparison, and interpretation.

Querying · Cleaning · Joins · Segmentation · Business Logic

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SQL Acquisition Funnel Analysis

Focus:
GA4 ecommerce data · BigQuery SQL · Funnel progression · Traffic source quality

A session-level SQL analysis comparing how organic, direct, referral, and paid traffic sources moved through key ecommerce funnel stages.

Key insight:
High traffic volume did not equal high commercial value.
The strongest channels were identified by downstream purchase efficiency, not sessions alone.

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Stability Over Speed

Focus:
World Bank data · SQL transformation · Comparative analysis · Tableau dashboarding

A SQL and Tableau case study reframing post-COVID recovery beyond GDP headlines by comparing GDP rebound with inflation pressure across five major economies.

Key insight:
GDP rebound alone gave an incomplete view of recovery. When inflation was included, the interpretation of economic stability changed.