SQLPage Exec

[T-Doschke]

Right now sqlpage stops rendering page while waiting for exec command to be finished.
Sometimes you want only to start a process but result of process is not of interest for rendering page.
Give sqlpage.exec a new parameter to choose if we want to wait or only start a process.

[lovasoa]

Indeed, it would be really nice if we had a background processing feature. Not only for sqlpage.exec; but for all sqlpage code. Would you be interested in participating in the design and implementation of this feature, or sponsoring it ?

In the meantime, the best you can do is have the process you execute with sqlpage.exec start a subprocess and detach from it. For instance:

start.sql

select
  'redirect' as component,
  'track_status.sql?process=' || sqlpage.exec('python3', 'daemon.py') as link;

track_status.sql

-- keep refreshing the page until the process is done to show live updates
select 'shell' as component,
    case when not exists (select 1 from my_timeline where timeline_id = $process and title = 'done')
        then 1 -- refresh every 1 second
    end as refresh;

select 'timeline' as component, TRUE as simple;
select date, title from my_timeline where timeline_id = $process;

daemon.py

import sys
import time
import sqlite3
import subprocess

conn = sqlite3.connect("./sqlpage/sqlpage.db")
sql = "INSERT INTO my_timeline (timeline_id, title) VALUES (?, ?)"


def update_timeline(timeline_id: int, title: str):
    with conn as cursor:
        cursor.execute(sql, (timeline_id, title))


def parent():
    timeline_id = int(time.time() * 1000)
    sys.stdout.write(str(timeline_id))

    subprocess.Popen(
        [sys.executable, __file__, str(timeline_id)],
        stdin=subprocess.DEVNULL,
        stdout=subprocess.DEVNULL,
        stderr=subprocess.DEVNULL,
    )
    update_timeline(timeline_id, "started")


def worker(timeline_id: int):
    for i in range(3):
        update_timeline(timeline_id, f"Step {i+1}")
        time.sleep(2)
    update_timeline(timeline_id, "done")


if __name__ == "__main__":
    if len(sys.argv) < 2:
        parent()
    else:
        timeline_id = int(sys.argv[1])
        worker(timeline_id)

Screencast.From.2025-10-28.17-27-02.mp4