MySQL : How to order by two or more columns and the NULL's value will be last?

Question

Trying to order the column name is not null as first, if the first column is null but not second column is not null etc..

Table :

id  name1 name2  name3
1.   a     b      
2.   a1            c
3.         b1      c1
4.                 c2
5.                 c3
6.   a2    
7.         b2      c4
8.   a3

Expected result

id 
1 
2
6
8
3
7
4
5   

I have tried to use COALESCE AND IFNULL But it's return zero result.

Answer 1

As documented under COALESCE( value ,...) :

Returns the first non- NULL value in the list, or NULL if there are no non- NULL values.

 mysql> SELECT COALESCE(NULL,1); -> 1 mysql> SELECT COALESCE(NULL,NULL,NULL); -> NULL 

As documented under IS NULL :

Tests whether a value is NULL .

 mysql> SELECT 1 IS NULL, 0 IS NULL, NULL IS NULL; -> 0, 0, 1 

Therefore:

SELECT   id
FROM     Table1
ORDER BY COALESCE(name1, name2, name3) IS NULL,
         COALESCE(name1, name2, name3)

See it on sqlfiddle .

This sorts first on whether all three columns are NULL (those that are will have an IS NULL result of one, which will come after those that aren't with a result of zero); then by the actual value of the first non- NULL column.