SQL Server
A practical SQL Server path: start with how EXISTS, IN, and JOIN actually behave, handle intermediate results with CTEs and temp tables, unlock APPLY and window functions, summarize with ROLLUP/CUBE, and finish with sharding vs multi-tenancy for scale.
What you'll learn
Follow in order: each step builds on the previous one.
- 1
EXISTS vs IN vs JOIN in SQL Server
Understand the practical difference between EXISTS, IN, and JOIN in SQL Server using simple examples and learn when each one makes sense.
- 2
CTE vs Temp Table vs Table Variable
A short, practical comparison of CTEs, temp tables, and table variables in SQL Server with examples.
- 3
CROSS APPLY vs OUTER APPLY in SQL
Learn how CROSS APPLY and OUTER APPLY work in SQL Server through practical examples including latest records, Top N per group, optional child records, and table-valued functions.
- 4
SQL Window Functions, Practically
Learn how SQL Server window functions simplify common query problems such as latest records, running totals, row comparisons, and Top N per group with practical examples.
- 5
ROLLUP vs CUBE in SQL Server Guide
ROLLUP generates hierarchical subtotals and a grand total, while CUBE generates subtotals for every possible combination of grouped columns.
- 6
Database Sharding vs Multi-Tenancy
Understand the difference between database sharding and multi-tenancy, why each is used, when you need them, and how both can work together in a scalable SaaS application.