Split a comma-separated record into its own rows

I have the following table, named stores:

store_id INT
emails VARCHAR

That contains values: store_id | emails --- | --- 1 | user_1@example.com,user2@example.com 2 | uswe3@example.com,user4@example.com 4 | admin@example.com And I want to generate the following set: store_id | emails --- | --- 1 | user_1@example.com 1 | user2@example.com 2 | uswe3@example.com 2 | user4@example.com 4 | admin@example.com As you can see I want to split the emails field into a separate record containing only one email address. Do you have any idea how I can do that? So far I managed to create the following query:

select store_id,string_to_array(emails,',') from stores

But I don't know how I can split the string_to_array to its own row.