What is the main function of the ORDER BY keyword in SQL?

The main function of the ORDER BY keyword in SQL is to sort results in ascending or descending order. When querying a database, it’s often essential to present the data in a specific order based on one or more columns. The ORDER BY clause allows users to define which column(s) should be used for sorting the result set, and whether that sorting should be in ascending or descending order.

For example, if you want to retrieve a list of customers sorted by their last names, you would use the ORDER BY clause followed by the column name for the last names. By default, this sorting is done in ascending order, but you can specifically request descending order by including the DESC keyword after the column name.

In contrast, the other options refer to different SQL functionalities. Merging tables based on a common field pertains more to JOIN operations in SQL. Grouping data by specific criteria relates to the GROUP BY clause, which aggregates data into summary rows based on unique values in specified columns. Filtering results according to specified conditions is accomplished using the WHERE clause, which restricts the rows returned by the query based on certain criteria. Therefore, the focus of the ORDER BY keyword is specifically on the organization of the output rather than on grouping, filtering, or merging data.