Postgres 12

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create table ImportH (host_media varchar(200))
insert into ImportH values ('[''email'', ''phone'', ''facebook'']')
1 rows affected

create table Media (media varchar(50))
with trimed as
(select substring(host_media from 2 for length(host_media)-2) as clean_col
from ImportH
)
insert into Media (media)
select unnest(string_to_array(clean_col, ',')) 
from trimed;
3 rows affected

select * from ImportH;

host_media

['email', 'phone', 'facebook']

select * from Media;

media

'email'

 'phone'

 'facebook'