Problems

Choose a topic to see problems in SQL.

• Advanced Queries 9
• Aggregation & GROUP BY 10
• Airline Operations 4
• Analytics Case Studies 6
• Anti & Semi Joins 4
• Appointments & Scheduling 4
• Attendance & Shifts 5
• Banking & HR Case Studies 5
• Blog Comments & Moderation 4
• Calendar & Date Dimension 4
• Calendar Grouping 4
• Car Rental Operations 4
• CASE & Conditional Aggregation 6
• Correlated Subqueries 5
• Crop Yield Analysis 4
• CTE & Recursive Queries 7
• Customer Segmentation (RFM) 4
• Customer Support Tickets 4
• Data Cleaning 5
• Data Modification & Set Operations 10
• Data Quality Checks 4
• Date & String Functions 10
• Date Arithmetic 3
• DDL & Constraints 7
• Derived Tables 4
• Duplicates & Deduplication 4
• Education & Grades 5
• Elections & Voting 4
• Energy Meter Billing 4
• Event Ticketing 4
• Filtering & Sorting 9
• Fitness Tracking 4
• Fraud & Risk Queries 4
• Gaming Analytics 4
• Gaps and Islands 3
• Healthcare Queries 4
• Hierarchical Data 4
• Hotel & Booking Systems 4
• HR Analytics 5
• Insurance Claims 4
• Integrity & Constraints 4
• Interview Classics 6
• Inventory & E-commerce Cases 5
• Join Types Deep Dive 5
• Joins 10
• JSON & Semi-structured Data 3
• LEAD & LAG Scenarios 3
• Library Systems 4
• Loans & Repayments 4
• Logistics & Delivery 4
• Marketplace Sellers 4
• Multi-Table Reports 4
• Music Streaming Charts 4
• NULL Handling 5
• Online Course Analytics 4
• Order Fulfillment Pipeline 4
• Pairing & Matching Queries 3
• Parking Lot Records 4
• Pattern & Range Filtering 4
• Payroll Calculations 4
• Percent & Share Calculations 4
• Pharmacy & Prescriptions 4
• Pivot & Unpivot 3
• Procedural SQL 3
• Product Reviews 4
• Project & Task Tracking 4
• Query Optimization 4
• Query Patterns 4
• Ranking & Top-N 5
• Ranking Edge Cases 5
• Real Estate Listings 4
• Reconciliation & Balances 4
• Relational Division 3
• Restaurant & Food Delivery 4
• Ride Sharing Analytics 3
• Rolling Metrics 4
• Salary History (Slowly Changing Data) 4
• Sales Funnel & Conversion 4
• Schema Design 4
• Self & Cross Joins 2
• Sensor Data Analysis 4
• Set Operations 4
• Skills & Certifications 4
• Social Content Analytics 4
• Social Network Queries 5
• Sports & Leaderboards 3
• Statistics in SQL 3
• Streaming & Movies 4
• String Aggregation & Splitting 3
• String Validation & Regex 4
• Subqueries 9
• Subscription Metrics 4
• Subtotals & Pivoting 2
• Supply Chain Purchase Orders 4
• Survey & Ratings 4
• Telecom Usage 4
• Tenure & Attrition 4
• Text Analysis in SQL 3
• Time Series SQL 4
• Transactions & Concurrency 4
• University Enrollment 4
• Views, Procedures & Triggers 4
• Warehouse Stock Ledger 4
• Warranty & Repairs 4
• Web & Marketing Analytics 6
• Window Frames 5
• Window Functions 15