To calculate the average of a column using SQL, you can use the AVG() function. Here's an example of how you can do it: ```sql SELECT AVG(column_name) AS average_value FROM table_name; ``` Replace ...

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 ...

Index key columns are frequently used in WHERE clauses, JOIN conditions, and ORDER BY clauses to optimise database query performance. Use composite indexes for multi-column filtering and sorting.

This affects only the query's output and not the ordering of any columns in the Query window. For example, to list the dates and departure times in the AIRLINE.MARCH table in ascending order, you ...

SQL is the leading language for developing and querying databases, but it has a few quirks.In my last article, I shared 7 SQL mistakes to avoid.Now, let’s take a look at 9 best practices for ...

Query columns using Always Encrypted with SQL Server Management Studio Learn how to query columns in Always Encrypted using SQL Server Management Studio. Retrieve ciphertext or text values stored in ...

The same can't be said for other complex types such as XML, CLR and Spatial that are still on the waiting list. In this column, I focused on the JSON-to-rowset scenario. However, SQL Server 2016 also ...