Microsoft SQL Documentation - SQL Server

Sort and Filter Results in Transact-SQL (Part 3 of 7) | Programming Databases with T-SQL for Beginners

Transactions in SQL Server for beginners

Understanding the SQL Server CASE statement

Querying data using the SQL Case statement

Using a SQL Server Case Statement for IF/Else Logic

How to write readable T-SQL queries

SQL multiple joins for beginners with examples

How to resolve deadlocks in SQL Server