What is the purpose of the concat_ws function in MySQL?

The CONCAT_WS function in MySQL is used to combine multiple strings and separate them using a specified separator. This function joins multiple strings into one string, dividing them with the specified separator.

Syntax:
CONCAT_WS(separator, str1, str2, …)

In this case, the separator is the character used to separate the strings such as str1 and str2 that are being concatenated.

For example, the CONCAT_WS function can be used to combine the first name and last name with a space separator:
SELECT CONCAT_WS(‘ ‘, first_name, last_name) AS full_name
FROM employees;

Possible outcomes may include:
full_name
John Doe
Jane Smith
…

In the example above, the CONCAT_WS function uses a space as a separator to combine the first_name and last_name together, and names the column as full_name.