Query to display custom Text when columns having null values in SQL, MYsql

Here i am going to show how to display custom Text when there are NULL columns in SQL and MySql as follows...

I had a table name as Childs with the following values. and the query to show values is select Query

select * from Child

Childid	Childname	Adultid
1	ramu	3
2	venki	3
3	shyam	4
4	somu	5
5	kiran	8
6	phani	7
7	kavya	1
8	vanju	1
9	keerthi	6
10	malathi	null
11	venu	null
12	kishore	6

So now I want to display these null values as 0 / any text as we like.
In my case 0 for whom parents are not there.  

To do so the Query is as follows

select childid,childname,ISNULL(adultid,'0') as adultid from Child

And the Results are :-

Childid	Childname	Adultid
1	ramu	3
2	venki	3
3	shyam	4
4	somu	5
5	kiran	8
6	phani	7
7	kavya	1
8	vanju	1
9	keerthi	6
10	malathi	0
11	venu	0
12	kishore	6