CLSkills
SQL

SQL

Joins, window functions, CTEs, optimization, and pivots

5 skills

SQLPopularNew
beginner

SQL Joins

Write complex SQL joins (inner, outer, cross, self-joins)

sqljoinsqueries
SQLPopularNew
intermediate

SQL Window Functions

Use window functions (ROW_NUMBER, RANK, LAG, LEAD)

sqlwindow-functionsanalytics
SQLPopularNew
intermediate

SQL CTE

Write CTEs and recursive queries for hierarchical data

sqlcterecursive
SQLNew
advanced

SQL Optimization

Optimize SQL queries with EXPLAIN, indexes, and query rewriting

sqloptimizationperformance
SQLNew
intermediate

SQL Pivot

Create pivot tables and dynamic crosstab queries

sqlpivotcrosstab