Slava Rozhnev

create temp table import_data (...);
copy import_data from '/path/to/file' (format csv, ...);
insert into tablename (...) select .. from import_data where not exists (select from tablename where tablename.phone = import_data.phone) on conflict do nothing;

select 
  users.id, users.name, group_concat(country.country) as visited 
from 
  users
left join user_to_country on user_to_country.user_id = users.id
left join country on user_to_country.country_id = country.id
where u_status = 1 
group by users.id, users.name;

create table test(
  id SERIAL PRIMARY KEY,
  num int,
  t text,
  constraint u_constrainte unique (num, t) DEFERRABLE 
)

Можно ли как то сделать сортировку того что нужно обновить перед тем как собственно обновлять записи?

$response = '{"status":"success","1":{"transaction":"8025400","email":"Не указана","amount":"21.38","currency":"RUB","currency_amount":"20.00","comission_percent":"6.90","comission_fixed":"0.00","amount_profit":"20.00","method":"Не выбран","payment_id":"1618399991","description":"Покупка доступа на 2 дня","date":"2023-03-13 19:40:46","pay_date":"2023-03-13 19:40:46","transaction_status":"0","custom_fields":"null","webhook_status":"0","webhook_amount":"0"}}';
$data = json_decode($response, true);
$transaction_status = $data["1"]["transaction_status"];

if ($transaction_status == 0) {
  echo 'Статус транзакции = 0';
  exit(0);
} else {
  echo 'Статус транзакции не равен 0';
}

If both operands are numeric strings, or one operand is a number and the other one is a numeric string, then the comparison is done numerically.

If a string is compared to a number or a numeric string then the string was converted to a number before performing the comparison.