What is the function of “ORDER BY” in MySQL?

In MySQL, the ORDER BY clause is used to sort the query result set. It can arrange the result set in ascending or descending order based on one or more column values.

The purpose of the ORDER BY clause includes:

1. Sorting: By specifying a column name or expression, the result set can be sorted in a specific order. By default, sorting is done in ascending order, and the DESC keyword can be used for descending order.
2. Multi-column sorting: The ORDER BY clause allows sorting by multiple columns. When multiple columns have the same value, they can be sorted in the order of subsequent columns.
3. Grouping the query results: when using the GROUP BY clause in a query to group the results, the ORDER BY clause can be used to sort the grouped results.
4. Top or bottom: Using the ORDER BY clause, you can prioritize specific values to appear at the top or bottom. For example, you can use a CASE statement and the ORDER BY clause to place certain values at the top or bottom of the result set.

In conclusion, the ORDER BY clause in MySQL is used to sort query results so that data is presented in a specific order.