Split String Into Multiple Records

Is there a good way to split a string into multiple records?

Here is what I am trying to do...

I have a table "branch" with a column "branch_num" which has a comma
delimited list of numbers - the users weren't supposed to do this but they
did and now I have to fix it. We want to create a new table "branch_area"
and move this comma delimited list into this new table as multiple records
before dropping the "branch_num" from the "branch" table.

branch {
branch_id bigserial primary key,
branch_num varchar(255)
}

branch_area {
branch_area_id bigserial primary key,
branch_id bigint foreign key to branch,
branch_num varchar(10)
}

I want to migrate the data something like this:

insert into branch_area
(branch_id, branch_num)
select
branch_id,
-- This is the part I need help with -> split branch.branch_num on ','
from branch
;

Is there a good way (or alternative way) to do this?

Thanks!

--
==================================================================
Aaron Bono
Aranya Software Technologies, Inc.
http://www.aranya.com
http://codeelixir.com
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