How to realize with single query "all, except in list"? - mysql

Question

I need to realize logic "All, except in list" with single query to show a widget on all routes, except listed.
I have next query:
SELECT *
FROM widgets w0_
LEFT JOIN widget_route w1_
ON w0_.id = w1_.widget_id
LEFT JOIN routes r2_
ON w1_.route_id = r2_.id
WHERE r2_.id IS NULL OR w1_.id = 3
Where 3 is an ID of current route, that I have dynamically. But I need to except widget from routes, listed in widget_route table
There is table structure:
widgets:
id, name, published
widget_route:
id, widget_id, route_id
routes:
id, name, path
Can anybody help me?

Answer 1

This is how you select all widgets without any entry in widget_route
by inner select:
SELECT
*
FROM widgets w
WHERE w.id NOT IN (SELECT
wr.widget_id
FROM widget_route wr);
by left join:
SELECT
*
FROM widgets w
LEFT JOIN widget_route wr ON wr.widget_id = w.id
WHERE wr.id IS NULL;
This is how you select all widgets not linked to your route with id 3 by widget_route:
by inner select:
SELECT
*
FROM widgets w
WHERE w.id NOT IN (SELECT
wr.widget_id
FROM widget_route wr
WHERE wr.route_id = 3);
by left join:
SELECT
*
FROM widgets w
LEFT JOIN widget_route wr ON wr.widget_id = w.id AND wr.route_id = 3
WHERE wr.id IS NULL;