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I have a QGIS Geopackage for a layer and I want to update the "Coverage" column based on the contents of the "ID_1" column. In the example below, the ID_1 column contains 1,2,3 or 4 separate entities (each starting with "E" and separated by "|"). I'd like the Coverage column to represent that number, e.g. 1,1,2,1,2,3 for the first few rows.

In Excel I would just count the number of "E" in the column. How can I do that in QGIS, I have tried 'count' in the field calculator, but for every row, I get to total number of rows in the whole ID_1 column, not the number of E in each row.

The other option would be to paste the column from my Excel into the coverage column in QGIS, but I can't select a whole column in the QGIS Table - is that possible? This layer contains geometry so exporting it as a csv and then reimporting it won't work (I assume). enter image description here

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  • Please provide the complete expression you tried for count(). Also, you assumption is wrong.
    – Erik
    Commented Sep 6, 2022 at 11:17

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The count() function is not what you are looking for, since it is an aggregate function (it looks across all features in your layer).

How about this:

length( regexp_replace( "ID_1", '[^E]+' ,''))

Basically it deletes all characters (except for the E), than the lenght function counts the number of surviving characters ;)

enter image description here

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    The answer works perfectly and thank you for the explanation of why count() didn't work, and what your function does to get the result.
    – WillH
    Commented Sep 6, 2022 at 22:59

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