MySQL: update single table one column data to another column

Question

I have a MySQL table called Cars. The Cars table has three columns: id int auto increment, foo varchar(255), bar varchar(255).

I want to simply update all rows in the Cars table into the bar column with the same value from foo if foo is not null. So both foo and bar will have the same value after the update wherever foo is not null.

Answer 1

update cars set
bar = foo
where foo is not null