What is the advantage of CONCAT_WS() function over CONCAT() function when we want to concatenate values ​​in columns and the value of any column is NULL?

We know that if any parameter is NULL, the CONCAT() function will return NULL, but only when the first parameter (ie, the separator) is NULL, CONCAT_WS( ) function will return NULL, and it will ignore any other NULL. When we want to concatenate the values ​​in a column and the value of any column is NULL, we can say that this is the advantage of CONCAT_WS() function over CONCAT() function. To understand it, let's consider the example from the table "Student_name;" There is the following data in it-

mysql> Select * from Student_Name;
+---------+-------+---------+
| FName   | Mname | Lname   |
+---------+-------+---------+
| Rahul   | NULL  | Singh   |
| Gaurav  | Kumar | NULL    |
| Harshit | NULL  | Khurana |
| Yash    | Pal   | Sharma  |
+---------+-------+---------+
4 rows in set (0.00 sec)

Now, suppose we want to concatenate the values ​​of Fname, Mname and Lname columns, the output is as follows-

mysql> Select CONCAT(Fname,Mname,Lname)AS Name from Student_Name;
+---------------+
| Name          |
+---------------+
| NULL          |
| NULL          |
| NULL          |
| YashPalSharma |
+---------------+
4 rows in set (0.00 sec)

But, if we use CONCAT_WS() function, then It will ignore NULL as shown in the following query -

mysql> Select CONCAT_WS(' ',Fname,Mname,Lname)AS Name from student_name;
+-----------------+
| Name            |
+-----------------+
| Rahul Singh     |
| Gaurav Kumar    |
| Harshit Khurana |
| Yash Pal Sharma |
+-----------------+
4 rows in set (0.00 sec)

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