sql - Append + symbol to ISD Code in Sqlite, Mysql -

i have database country list, have column in country table named 'isd_code' want append + symbol before each isd code through sql. there query or shortcut because tried excel has + symbol appended when import in sqlite removes + symbol. please me.

to retrieve data symbol prepended:

select '+' || isd_code country 

to permanently update table:

update country set isd_code = '+' || isd_code