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When I create a atlas for species distribution from a database (one line for each record) I collect geometries to get a multigeomtry layer (one line for each species) and generate a atlas. Works fine.

But I did not find a way to get different symbols for different years of record. Only way I found is "rule based" by hand. Is there any other way I missed to automate atlas generation for >100 species and get different symbols for different years?

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    Just to be sure I understand well your question : you have a table with species and year for each record, you create a multigeometry layer (record grouped by species) and you utilise this new layer as the coverage layer for your atlas (so you get one page for each different species). Your question is how to symbolise each year differently on each page of your atlas. I am right ?
    – J.R
    Aug 7, 2023 at 16:03
  • yes & yes !! But the multigeometry layer is just my way to get it into atlas generation, if there is a another way, I am not sticking to it.
    – user16032
    Aug 8, 2023 at 8:08

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After creating your multigeometry layer (record grouped by "Species_Field") use it to generate your atlas using the "Species_Field" (the one you have used to group the geometry), dont' forgot to check the "Hidden coverage layer" setting (you may also uncheck the layer in the layer panel next steep will be easier visualise) and to set the map item properties to "Controlled by Atlas" if needed.

Then you have to set the symbology of your original layer.
To only display the active specie in the atlas page set a rule based styling with "Species_Field" = @atlas_pagename as rule (if needed you may also add an "ELSE" rule to display all other species with a different symbol)

You now have an atlas that display each species on its own page. To get each species to be symbolized by year of record you just need to right click on the rule and choose "Refine Current Rule" (if needed you may again do the same with the ELSE rule). This will let you add a categorization based on your year of record field.

enter image description here

This will result in an atlas where each page display one species and where each reccord is symbolised by year of reccord (but all species will share the same symbology and look the same) enter image description here

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  • thanks! worked like a charm! but one follow up question: is there any ressource, how-to, manuel or anything where to look up such things or do have to figure it out myself? (or hope a kind soul will answere it here?) thanks a lot!
    – user16032
    Aug 8, 2023 at 10:04
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    @user16032 not really, there is the desktop user guide/manual and tutorials in the QGIS Training manual (see here qgis.org/en/docs/index.html) but this cant cover all use case nor all tricks so in the end looking for specific tutorial on internet or asking here is the way to go...
    – J.R
    Aug 8, 2023 at 10:16

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