Insurance – ESN Data (Openclassroom)

SQL Practice : Housing Insurance

Fictional

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14/12/2024 > 30/12/2024


Context

I completed this project for ESN Data (fictional) as part of my Business Intelligence Analyst training. The goal was to create and manage a relational database to analyze the French housing insurance market. I helped a fictional insurance company structure its data, load a dataset of contracts and a geographical reference file, and write SQL queries to extract key indicators.

Datasets

  • CONTRAT.CSV – 30,335 housing insurance contracts (11 attributes)
  • REGION.CSV – 38,916 department-city pairs (7 attributes)

Workflow

  • Exploration and data dictionary in Excel (types, constraints, descriptions)
  • UML modeling, then relational schema via SQL Power Architect
  • CSV import into MySQL (inconsistencies cleaned via VLOOKUP)
  • Wrote 12 SQL queries (SELECT, JOIN, aggregations, ORDER BY, AVG/COUNT functions)

Insights

  • Top 5 contracts with the largest surface area: between 559 m² and 815 m²
  • Average monthly premium: €19/month
  • Declared value distribution: mostly under €25,000; only 104 contracts over €100,000
  • “Integral” plans in Pays de la Loire: 589 occurrences
  • Houses in department 71: 48 contracts, evenly split between Classic and Integral plans
  • Average surface area in Paris: 52 m²
  • Top 10 departments by average premium: Paris (€36), Hauts-de-Seine (€26), Val-de-Marne (€20) etc.
  • Most covered city: Paris
  • Most active region: Île-de-France (14,177 contracts)

These results highlight the strong concentration of contracts in Île-de-France, disparities in premium amounts across regions, and the profiles of insured properties.

Business Impact

Through this project, I developed hands-on skills in database design and SQL querying—essential for any BI Analyst. The insights can help the insurer:

  • Prioritize tailored offers in high-premium areas (e.g. Paris)
  • Adjust insurance plans based on declared value distribution
  • Target prospecting campaigns in under-covered cities

Internally, these deliverables (schema, SQL code, screenshots) serve as a reference for future analyses and support data-driven decision-making.

Links

Technical document

List of analysis

Methodology