MySQL: How to return only one row based on criteria within a resultset

I have the following table:

id | group | value 
1  |   1   |   10
2  |   1   |   20
3  |   1   |   30
4  |   0   |   20
5  |   0   |   20
6  |   0   |   10

I want to return the h开发者_如何学Cighest value where the group is 1 (=30) and all of the values where the group is 0, into one resultset.

I have to do this in one statement, and I guess I should use an IF statement within a SELECT statement, but I can't work out how. Can anyone help to point me in the right direction?

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(select max(value) from the_table where group = 1)
union
(select value from the_table where group = 0)

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If (group +value) is unique, you can also do it without union (as proposed by Ray Toal)

SELECT a.value
FROM table1 a    
WHERE a.`group`=0 or (a.`group`=1 AND a.value = 
 (SELECT MAX(value) FROM table1 b WHERE b.`group`=1))