T-SQL is more than syntax. Production SQL Server work demands safe query patterns, predictable performance, clear concurrency behaviour, and robust security and operational controls. This book is a practical guide to T-SQL patterns for SQL Server. It covers query building, data modification, index design, performance tuning, security, stored procedures, functions, views, ETL, temporal data, concurrency, testing, monitoring, disaster recovery, migrations, and automation with GitHub Actions. Each chapter includes implementation-focused examples you can lift into real systems. The examples prioritise correctness, readability, and operational safety.