does mysql stored procedures support data types like array, hash,etc?

i am creating a mysql function which takes in a varchar and change it to a int based on a mapping table.

select name, convert_to_code(country) from users where sex = 'male'

here, the convert_to_code() function takes in a country name (e.g. Japan, Finland..) and change it to country code which is an integer (e.g. 1001, 2310..) based on a mapping table called country_maping like below:

country_name (varchar) | country_code (int)
Japan                  | 1001
Finland                | 2310
Canada                 | 8756

currently, the stored function need to select country_code from country_mapping where country_name = country_name and return the query result. is that possible to create a hash data struct in SP to optimize the process so that it will not need to perform the query for each row matches the where clause.

thanks in advance!

From stackoverflow

• You should just use the table as you're doing.

  If you create a covering index over those two columns, it should make it as efficient as possible.