A micro web app example for Omnigres (https://github.com/omnigres/omnigres) (README.md candidate)

0_motd.sql

create table if not exists motd
(
    id        int primary key generated always as identity,
    content   text,
    posted_at timestamp default now()
);

create or replace function show_motd() returns setof omni_httpd.http_response as
$$
select
    omni_httpd.http_response(body => 'Posted at ' || posted_at || E'\n' || content)
from
    motd
order by
    posted_at desc
limit 1;
$$ language sql;

create or replace function no_motd() returns setof omni_httpd.http_response as
$$
select omni_httpd.http_response(body => 'No MOTD');
$$
    language sql;

create or replace function update_motd(request omni_httpd.http_request) returns omni_httpd.http_response as
$$
insert
into
    motd (content)
values
    (convert_from(request.body, 'UTF8'))
returning omni_httpd.http_response(status => 201);
$$
    language sql;

update omni_httpd.handlers
set
    query = (select
                 omni_httpd.cascading_query(name, query order by priority desc nulls last)
             from
                 (values
                      ('show', $$select show_motd() from request where request.method = 'GET'$$, 1),
                      ('update', $$select update_motd(request.*) from request where request.method = 'POST'$$, 1),
                      ('fallback', $$select no_motd() from request where request.method = 'GET'$$,
                       0)) handlers(name, query, priority));

1_example

$ http GET localhost:8080
HTTP/1.1 200 OK
Connection: keep-alive
Server: omni_httpd-0.1
content-type: text/plain; charset=utf-8
transfer-encoding: chunked

No MOTD

$ http localhost:8080 --raw "Check out Omnigres"
HTTP/1.1 201 OK
Connection: keep-alive
Server: omni_httpd-0.1
transfer-encoding: chunked

$ http localhost:8080
HTTP/1.1 200 OK
Connection: keep-alive
Server: omni_httpd-0.1
content-type: text/plain; charset=utf-8
transfer-encoding: chunked

Posted at 2023-03-23 02:59:14.679113
Check out Omnigres

$ http localhost:8080 --raw "First release is coming"
HTTP/1.1 201 OK
Connection: keep-alive
Server: omni_httpd-0.1
transfer-encoding: chunked

$ http localhost:8080
HTTP/1.1 200 OK
Connection: keep-alive
Server: omni_httpd-0.1
content-type: text/plain; charset=utf-8
transfer-encoding: chunked

Posted at 2023-03-23 02:59:28.771903
First release is coming