Trying to understand OC ... Layouts 1

Hi All
Please bear with me... I am a little slow and tend to jump to wrong conclusions so please be patient

So my thinking so far is that there are core layouts used by OC but if I use design>layout then i could change these
I also think that the route part determines different ways of navigating to similar layouts
I assume that if i use the same route as an existing one but different sort order the first layout would appear then the next higher sort order appear

I thought I would experiment by creating a new about us layout with a route of About_us and sort order 100
when nothing appeared i edited the about us layout and could not see the new about us to edit....

checking error logs i found …

2019-09-06 9:34:00 - PHP Notice: Error: Duplicate entry '0' for key 'PRIMARY'<br />Error No: 1062<br />INSERT INTO oc_layout_module SET layout_id = '15', code = 'links_bymona.62', position = 'content_top', sort_order = '100' in /var/sites/m/mybutcher.shop/public_html/t3/system/library/db/mysqli.php on line 41

can anyone explain what I am doing wrong please

thanks

george

Hi
Make sure that primary key of table is AUTO_INCREMENT
OR mention opencart version so able to check
Thanks

thanks... I shouldn't need to do that... I seem to keep losing stuff like this in Opencart too often...

seems flaky that this can happen...

anyone that is sorted thank you... it doesn't help me understand how I can easily see the designs of each page on the theme
that is really really annoying...

Is there any framework which allows you to load up a site's assets and make changes to the various pages in realtime rather than hunt each file and edit it...

or at the very least is their a php editor (been a while since I cut code - i used to use dreamweaver) where you could load the code and preview the page???

surely somebody has written this???

george