SQL & PL/SQL :: Update Name With Single Space Between Words

In the table the names are having diffrent spaces for one name only one space between the words,for another name two spaces between words,for other names three spaces between the words.

I want to update with single space how can we that.

I am giving the data as follows.

CREATE TABLE student(sname VARCHAR2(30));

INSERT INTO student VALUES('PRAKASH BABU');
INSERT INTO student VALUES('RAJESH KUMAR');
INSERT INTO student VALUES('POORNA CHANDAR');
INSERT INTO student VALUES('ANIL RAJ');
INSERT INTO student VALUES('ABHI RAM KONA');
INSERT INTO student VALUES('SRI TEJA MEDI');

Like this the table contains millions of rows.

I want to update the names like this.

PRAKASH BABU
RAJESH KUMAR
POORNA CHANDAR
ANIL RAJ
ABHI RAM KONA
SRI TEJA MEDI