Problems/Coding/SQL/Medium

Medium SQL

Coding problems · 40 total

Write complex JOIN with multiple tables

Use self-join for hierarchical data

Implement correlated subquery

Use window functions (ROW_NUMBER, RANK)

Calculate running totals with window functions

Use LAG and LEAD functions

Implement pivot table with CASE

Use CTE (Common Table Expression)

Write recursive CTE

Use UNION ALL vs UNION

Optimize query with proper indexes

Use EXPLAIN to analyze query

Implement pagination with LIMIT/OFFSET

Use CASE with aggregate functions

Filter with complex WHERE conditions

Use COALESCE in JOIN conditions

Implement data validation with CHECK constraint

Use FOREIGN KEY constraints

Create view with CREATE VIEW

Use stored procedure

Implement transaction with BEGIN/COMMIT

Handle errors with TRY/CATCH

Use MERGE for upsert operations

Implement full-text search

Use JSON functions for JSON data

Parse and query JSON columns

Use array functions

Implement data archiving strategy

Use partitioning for large tables

Optimize query with query hints

Use materialized views

Implement data deduplication

Use window frame specification

Calculate percentiles with window functions

Use FIRST_VALUE and LAST_VALUE

Implement gap and island problems

Use CROSS JOIN for cartesian product

Implement conditional aggregation

Use PIVOT and UNPIVOT

Optimize subquery performance