QGIS - atlas print composer how to display mutiple values when adding attribute table?

Question

I have this attribute table. I locked my atlas generator by county. For each, I want the statistics of all the cities that are in each county. For example : If the page of SICARIO is showed I want :

• Trapani
• Palerme
• Catane

Like so :

For instance, I achieved showing just the statistics for one city for each county using this expression

"city_name" || ' : '|| round(( "people_ok" *100)/ "total_of_people") || '% of people are ok and'|| round(( "people_not_ok" *100)/ "total_of_people") || '% are not' , like that :

How can I do to tell QGIS to show ALL the cities that belong to SICARIO ?

While knowing that:

• for SICARIO I have to display 3 cities
• for RADEON 2 cities
• for TUNEM 3 cities

It's unclear to me why when adding the attribute table, only the first line that matches is displayed.

Answer 1

If you have everything on one layer (as it seems to be the case), you should use aggregate functions and filter the aggregated city_names by conty_name to create an array with all cities in a county using array_agg() function. From this array, loop through each element (city) to get the respective attribute values for the fiels people_ok and people_not_ok.

Edit: I tested your sample project and had to make only small adjustments. Use a text layout element, not an attribute table layout element, to introduce this text, as you don't really need an attribute table element for this, you use it to create a text, containing different attribute values concatenated. HOwever, the expression also works if you intreroduce it in the attribute table layout element.

Use the expression below:

with_variable(
    'county',
    county_nam,
    array_to_string(
        array_foreach(
            array_agg (
                city_name, 
                filter:="county_nam"=@county
            ),
            @element 
            || ': ' ||
            attribute(
                get_feature('counties_cities','city_name', @element),
                'people_ok'
            )
            || ' % of people are OK and ' ||
            attribute(
                get_feature('counties_cities','city_name', @element),
                'people_not'
            )
            || ' % are not'
        ),
        delimiter:= '\n' 
    )
)