Query Optimizer Phases

The SQL Server Query Optimizer uses cost-based optimization to create an execution plan with the least cost.

Parent Table vs Child Table

Understanding the difference between Parent Tables and Child Tables and the difference between Primary Keys vs Foreign Keys.

Selecting From Mulitple Tables

How to write T-SQL SELECT statements using multiple tables and what are the differences between using Inner Joins, Left Outer Joins, Right Outer Joins, and Full Outer Joins.


The SQL Coalesce function is used to when you want to combine values from a series of columns or expressions when they might contain NULL values.

What is a Function?

What is a SQL Function and how to use a function in a T-SQL statement? We use the GetDate() and LEFT() functions as examples.