这是我的函数，执行这个函数时返回错误:
create or replace function country(varchar)
returns customer(customer_id integer,
first_name varchar,
last_name varchar) as $$
select customer_id, customer.first_name, customer.last_name
from customer
inner join address on customer.address_id = address.address_id
inner join city on address.city_id = city.city_id
inner join country on city.country_id = country.country_id
where country = '$1';
$$
language sql;
返回查询时出错。
为此解决方案使用创建类型:
create type ct as (customer_id integer, first_name varchar, last_name varchar)
现在创建函数
create or replace function country(varchar)
returns ct as $$
select customer_id, first_name, last_name from customer
inner join address on customer.address_id = address.address_id
inner join city on address.city_id = city.city_id
inner join country on city.country_id = country.country_id
where country = $1;
$$ language sql;
或者使用这个
create or replace function country(varchar)
returns table(customer_id integer,
first_name varchar,
last_name varchar) as $$
select customer_id, customer.first_name, customer.last_name
from customer
inner join address on customer.address_id = address.address_id
inner join city on address.city_id = city.city_id
inner join country on city.country_id = country.country_id
where country = $1;
$$language sql;