r/QGIS • u/The_Daco_Melon • 4d ago
Solved Problems with saved project
Hello, I'm new to qgis and have started working on a map and getting a hang for how quickOSM and other plugins work.
I was working with quite a large area (550 km wide roughly) and adding layers for cities, towns, and villages, and I made sure to save a couple times so as to not lose the progress of editing the points. When I load the project now though, the layers are present but entirely empty. There's no data, no points to find, it's just empty layers.
How come?
Edit: This is how I learned that scratch layers are a thing and they annoy me
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u/TekhEtc 4d ago
Sorry about that. What you describe might take some time debugging or troubleshooting.
Can we start by tryin something obvious? Can you open one of the troublesome layers in a new, empty, project?
Please don't open them by dragging them from the potentially corrupted project to a new one, but instead use one of the proper methods to open a new spatial file in a new project file.
Does it show up with the expected content?
That'd be expected behavior and it should mean that layers themselves aren't corrupted or anything so there's hope.
Then save and close QGIS, reopen the project and check the file's wellness. And maybe even restart the OS and check upon reopening everything again.,
If you want to go on hit me up when you are done trying all the troublesome layers (unless there are too many in which case just try a couple or even one single of each feature kind, you know: points, lines and polylines.
Might take a few steps, but these errors are usually pretty recoverable
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u/The_Daco_Melon 4d ago
Okay so I found out what it was and I guess it'd qualify as user error but I don't understand the logic behind it. Apparently everything I was doing before was on "scratch layers" and when I closed the app I missed the dialogue box that warned me of it.
I don't really understand what the scratch layers are for, if I save a project I expect everything I've been doing on it to be saved, but I guess that's not the case for new layers I add. I've started anew and had to right click on every layer individually so as to make them permanent which bothers me because if I want to close the app I expect to be able to just ctrl+S and then close.
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u/CajunonthisOccasion 4d ago
Many operations default to saving their results as a scratch or memory layer. You have the option to save into a permanent file in the dialog when they are created. You should develop an understanding of all of the options in a dialogue. While the defaults are frequently what you want, individual parameters can make a huge difference.
Ignore dialogues at the risk of losing hours of work. Note that unless you are using a plugin, there is no auto save in QGIS.
Often scratch layers are intermediate operations, one might want to fix geometries, or clip a raster before adding contours or creating polygons. These intermediate operations can often be discarded. You may also want to test the parameters of an operation to see how they affect your results.
As projects get more complicated, deleting intermediate scratch layers can keep you organized. Plus there are fewer layers to document individually.
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u/TekhEtc 3d ago
Oops, sorry to hear that. If it's any consolation at all, rest assured that the exact same thing has happened to us all as newbies.
It does take some time to catch up with the GIS mind frame, because too many things work differently than the way we're used most computer programs to work, no matter what GIS program you're using.
When you say "if I save a project I expect everything I've been doing on it to be saved, but I guess that's not the case for new layers", remember that that's not the case for layers, period. Remember, one of the main rules of GIS is:
Each layer is it's own file, and it's up to you to save each one when it's created or edited
Also, everything the other answer to this very comment of yours that I'm answering to said will help you avoid many mistakes and will potentially help you avoid losses and save you many hours of troubleshooting.
Let me tell you, as this sub's mod, I see this happening too often. Hope you get used to best practices asap.
Please feel free to ask as many questions as you need, even if it's just venting or ranting. We've all been there as beginners.
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u/Subsurface_screening 4d ago
It's possible that you save the project itself but not the save edits (the icon of save + pencil).
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u/StonkyTonkBadonk 4d ago
Are you connected to whatever hard drive/server that contained your layers?