Question

i have problem with CONCAT mysql function

Mysql Quesry is

SELECT CONCAT(a_firstname,' ',a_lastname) as a_employeename FROM employee.

This gives null if any of field is null

+--------------------------+
| a_firstname | a_lastname |
----------------------------
| bh          | a          |
| a           | NULL       |
+--------------------------+

Result

+----------------+
| a_employeename |
------------------
| bh             |
| NULL           |
+----------------+

Answer 1

MySQL treats NULL “no data”, So anything could be club with NULL become NULL.
So to avoid this you must put IFNULL(field,result).

See following query:

SELECT CONCAT(IFNULL(a_firstname,''),' ',IFNULL(a_lastname,'')) as a_employeename FROM employee

Thanks.