Read this SQL tutorial to learn when to use SELECT, JOIN, subselects and UNION to access multiple tables with a single statement.

When you execute a query using the LEFT JOIN syntax, SQL does two things: It returns all of the records from both tables that contain matching values, as defined by the ON clause.

Microsoft has just added support for query hints to Azure SQL Database, giving database administrators a powerful tool to manage the performance of ISV application code. Here's how it works.