Overview: Consistent SQL practice across varied platforms builds real job-ready confidence.Guided lessons help beginners, while timed challenges sharpen intervi ...

PolyBase, a data virtualization feature for SQL Server, allows users to seamlessly query data from various external sources directly using T-SQL (Transact-SQL) without the need for separate client ...

One of the most common problems when running SQL Servers is slow queries. The help desk or database team usually hears that described as the application is slow or ...

The structured query language is a powerful tool for connecting to many database systems that store data in tables organized into rows and columns. It's often used on the backend of business websites ...

A common SQL habit is to use SELECT * on a query, because it’s tedious to list all the columns you need. Plus, sometimes those columns may change over time, so why not just do things the easy way? But ...

Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement. It’s sometimes difficult to know which SQL syntax to use when ...

A free tool to reduce coding for developers who like to surface T-SQL database recordsets in a simple collection of customized POCO objects. Every so often, I find myself wishing that I had a utility ...