csvexportqgis
I have a layer with a table containing several columns.
If I right click on the layer –> Save as.. –> CSV and chose to only include my selection I get a nice CSV file with all columns for the selected objects.
However, I only want the data from one specific column to be exported to the CSV file.
How would I go around this?
You are doing fine, but just need to go to next step.
Tick on Save only selected features.
The 10-character limit for column names is a limitation of the shapefile format. So the easiest solution is to use format that allows longer column names, such as geopackage.
If for some reason you must use shapefiles, give each column a short name before importing into QGIS. In Excel, it would be very simple to add a row, fill the first value as "field1", then click and drag across the row to auto-fill with field2, field3, etc.
Now the first two rows of your spreadsheet are:
Save these two rows as a separate spreadsheet.
Delete the second row from the CSV before importing into QGIS.
You won't be able to import the original column names into a shapefile, because the 10-character field name limit still applies. But after any processing you do in QGIS, you can export the layer as a CSV and add the original column names. Open the exported CSV in Excel, make sure the columns are in numerical order, and insert the row of original column names.
Best Answer
After you selected your features, from the toolbar go to Layer > Save As.... Check the Save only selected features option and save it as a new shapefile (also add it to the map canvas for convenience by checking the Add saved file to map option).
Then from the toolbar, go to MMQGIS > Import/Export > Attributes Export to CSV File, select your layer and the column(s) you want exported.
Note, you may need to enable the MMQGIS plugin from Plugins > Manage and Install Plugins....
Hope this helps!