Questions every good Database/SQL developer should be able to answer

Basics

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1. SELECTing columns from a table
2. Aggregates Part 1: COUNT, SUM, MAX/MIN
3. Aggregates Part 2: DISTINCT, GROUP BY, HAVING

Intermediate

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1. JOINs, ANSI-89 and ANSI-92 syntax
2. UNION vs UNION ALL
3. NULL handling: COALESCE & Native NULL handling
4. Subqueries: IN, EXISTS, and inline views
5. Subqueries: Correlated
6. WITH syntax: Subquery Factoring/CTE
7. Views

Advanced Topics

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• Functions, Stored Procedures, Packages
• Pivoting data: CASE & PIVOT syntax
• Hierarchical Queries
• Cursors: Implicit and Explicit
• Triggers
• Dynamic SQL
• Materialized Views
• Query Optimization: Indexes
• Query Optimization: Explain Plans
• Query Optimization: Profiling
• Data Modelling: Normal Forms, 1 through 3
• Data Modelling: Primary & Foreign Keys
• Data Modelling: Table Constraints
• Data Modelling: Link/Corrollary Tables
• Full Text Searching
• XML
• Isolation Levels
• Entity Relationship Diagrams (ERDs), Logical and Physical
• Transactions: COMMIT, ROLLBACK, Error Handling