Updating data on mysql using PHPmyadmin problems


I have a problem, after moving hosts my database for some reason failed to backup correctly

I have two columns lets call them col_b and col_c showing data of 0 in about 30% of the entries when they should be 1

These should be a value of 1 if col_a is also 1

what UPDATE command can i use in PHPmyadmin to change the entries in col_b and col_c if the value of col_a is 1?

Thanks John

UPDATE tablename
SET column_b = 1
WHERE column_a = 1
AND   column_b = 0

Then repeat for column_c

Thank you