The default search term operator is AND
You can use brackets, AND OR and NOT to improve your search. For example: C# AND NOT ( VB or SQL )
A query of a single * will return everything, filtered by any filters.
Search by Author: author:"author name"
Filter by tag: tag:C# or tag:(C++ or Java)
Wildcard search use: "?" or "*" eg. gr?d or gr*
Martin will explain how to use the EXISTS clause within your subqueries in this video, which will further allow you to filter your records.
This video from our "SQL Database for Beginners" series will delve into subqueries and how to use them as a filter condition. You will learn how to narrow the results when querying, along with derived tables and when they can be used.