SQL Portfolio & Database Analytics

Advanced Data Analysis & Business Intelligence

What Can SQL Do for Your Business?

SQL (Structured Query Language) is the backbone of data-driven decision making. This portfolio demonstrates practical applications of advanced SQL techniques to solve real business problems.

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Customer Analytics

Understand customer behavior, segment audiences, and predict churn

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Revenue Analysis

Track sales trends, identify top performers, and optimize pricing

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Performance Metrics

Calculate KPIs, monitor trends, and benchmark against targets

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Predictive Insights

Identify patterns, forecast demand, and make data-driven decisions

Real-World Examples

Customer Segmentation
Sales Performance
Retention Analysis
Academic Records
RFM Customer Segmentation
Classify customers into strategic segments based on Recency, Frequency, and Monetary value to target marketing efforts effectively.
Customer Segment Count Avg Lifetime Value Marketing Action
Champions 1,247 $8,942 Reward with exclusive offers
Loyal Customers 3,521 $5,234 Upsell and cross-sell
At Risk 892 $4,156 Reactivation campaign
Can't Lose Them 234 $12,567 Win-back with high incentives
Recent Customers 2,103 $1,892 Onboarding and engagement
Business Impact:
  • 234 high-value customers at risk of churning - immediate retention focus needed
  • Champions represent only 15% of customers but 40% of revenue
  • 2,103 recent customers - optimize onboarding to convert to loyal segment
  • Targeted campaigns can increase retention by 25-30%
Monthly Sales Trend with Running Total
Track month-over-month sales performance with cumulative revenue to monitor growth trajectory.
Month Monthly Revenue Running Total Growth %
January 2024 $2,450,000 $2,450,000 -
February 2024 $2,680,000 $5,130,000 +9.4%
March 2024 $2,890,000 $8,020,000 +7.8%
April 2024 $3,120,000 $11,140,000 +8.0%
May 2024 $3,350,000 $14,490,000 +7.4%
Business Impact:
  • Consistent growth averaging 8.2% month-over-month
  • On track to exceed $40M annual revenue target
  • Q1 to Q2 shows acceleration - marketing campaigns driving results
Cohort Retention Analysis
Track customer retention by acquisition cohort to measure long-term engagement and identify successful periods.
Cohort Month Cohort Size Month 1 Month 3 Month 6 Month 12
Jan 2023 1,250 68% 52% 41% 35%
Apr 2023 1,580 72% 58% 47% 42%
Jul 2023 1,820 75% 62% 51% 46%
Oct 2023 2,100 78% 65% 55% -
Business Impact:
  • Retention improving significantly - Oct 2023 cohort up 31% vs Jan 2023
  • Product improvements in Q2 2023 driving higher engagement
  • Target: Achieve 50% 12-month retention for Q1 2024 cohorts
  • Strong retention = lower acquisition costs and higher LTV
Student Performance Ranking
Identify top-performing students by department for Dean's List, scholarships, and academic recognition.
Rank Student Name Department GPA Credits
1 Sarah Johnson Computer Science 3.98 120
2 Michael Chen Computer Science 3.95 118
3 Emily Rodriguez Computer Science 3.92 115
1 David Park Mathematics 3.97 122
2 Jennifer Lee Mathematics 3.94 119
Academic Insights:
  • Computer Science has highest concentration of top performers
  • 12 students qualify for Dean's List this semester (GPA ≥ 3.75)
  • Average GPA improving year-over-year: 3.41 → 3.58
  • Targeted tutoring for at-risk students (GPA < 2.5) showing positive results

SQL Techniques Demonstrated

Advanced Queries

  • Complex JOINs (Inner, Left, Right, Full)
  • Subqueries and CTEs
  • Window Functions
  • Recursive Queries

Analytics Functions

  • RANK(), DENSE_RANK(), ROW_NUMBER()
  • LAG(), LEAD(), FIRST_VALUE()
  • Running Totals & Moving Averages
  • Percentile Calculations

Business Intelligence

  • RFM Segmentation
  • Cohort Analysis
  • Customer Lifetime Value
  • Churn Prediction