Функции работы со строками

select 

first_name,

last_name,

concat(first_name, ' ', last_name),

first_name || ' ' || last_name,

trim(leading from ' ' || first_name || ' '),

substring(first_name || ' ' || last_name, 3, 10),

char_length(first_name),

upper(first_name),

lower(first_name),

trim('er' from first_name)

from 

actor;

select 

email,

substring(email, 1, strpos(email, '@') - 1),

strpos(email, '@'),

substring(email, strpos(email, '@') + 1)

from 

staff;