What is the method for concatenating SQL strings for a query?

In SQL, CONCAT() function can be used to concatenate strings. For example, the following is an example of using CONCAT() function to concatenate two field values:

SELECT CONCAT(first_name, ' ', last_name) AS full_name
FROM employees;

In the example above, the CONCAT() function concatenates the values of the first_name and last_name fields to create a full name, which is then returned as the full_name column. You can also use the || operator to concatenate strings, for example:

SELECT first_name || ' ' || last_name AS full_name
FROM employees;

Both of these methods can be used to concatenate string query results.