[Qgis-us-user] Newbie question about importing shapefiles and layers from Arcmaps

Judith_Kerman · March 3, 2022, 9:11pm

Thanks, all. The essential question is that, when I look under the hood at ArcMaps files, there are multiple files, for instance (shapefiles): .cpg, .dbf, .prj, .sbn, .sbx, .shp, shp.xml, shx.
If I try to bring them in one by one, I get invalid data type messages for .cpg, .sbn, .prj, .shp.xml and .sbx

The file types .dbf, .shx and .shp work fine, but all look the same, including the attribute table. They all have coordinate systems, and they overlay the way they should visually.

Similarly, the New York State Orthographic imagery has .aux, .j2w, .jp2, and .tab
When I bring in a file, I can bring in .aux, but QGIS flags it as having a Read Block error, and .jp2, which seems to be fine, shows the data just like it looks in Arcmaps, and seems to contain coordinates. For the other file types (.j2w and .tab), I get an invalid data type message.

I understand that to get raster files from Arcmaps itself, I have to export as a TIFF. That works fine, too, and again seems to have coordinates.

The question is: am I losing any data that is contained in the “invalid” files? Do I need all three of the kinds of shapefile subfiles that seem to work? They all have the same attribute table contents. Why would ESRI use 8 different subfiles for a “shapefile” and the NY Ortho use 4 (evidently needed for Arcmaps) if they contain only redundant information? Am I safe just using one of the ones that work, such as .shp and .p2, and not worrying about the rest?

Hope that makes the question clearer.

Followup question;:

It would be lovely to just be able to import my Arcmaps work instead of rebuilding everything. I understand SLYER is expensive. I found an open source plugin, Mxd2Qgs, that suppsedly would import my map packages, but I don’t understand the documentation. Suggestions?

Thanks! Glad I found this list!

Judy

rjhale1971 · March 3, 2022, 9:18pm

So that’s the confusing (sort of) nature of shapefiles.

shp holds the geometry
dbf holds the data
shx connects the two (at least I think I’m remembering this right)

QGIs knows if you add the shp it needs the other files and grabs those automatically - so there’s no need to add them. Same with the tiff - it grabs what it needs once you add the main file. You do need all the files - they aren’t redundant - you just don’t have to add them one by one to QGIS.

As far as converting work from QGIS ↔ MXD - Oh. That’s part of the pain. Someone on the main QGIS list asked about that tool the other day. I’ve not used it.

Randy

On Thursday, March 3, 2022 4:11:48 PM EST Judith Kerman wrote:

Thanks, all. The essential question is that, when I look under the hood at

ArcMaps files, there are multiple files, for instance (shapefiles): .cpg,

.dbf, .prj, .sbn, .sbx, .shp, shp.xml, shx.

If I try to bring them in one by one, I get invalid data type messages for

.cpg, .sbn, .prj, .shp.xml and .sbx

The file types .dbf, .shx and .shp work fine, but all look the same,

including the attribute table. They all have coordinate systems, and they

overlay the way they should visually.

Similarly, the New York State Orthographic imagery has .aux, .j2w, .jp2,

and .tab

When I bring in a file, I can bring in .aux, but QGIS flags it as having a

Read Block error, and .jp2, which seems to be fine, shows the data just

like it looks in Arcmaps, and seems to contain coordinates. For the other

file types (.j2w and .tab), I get an invalid data type message.

I understand that to get raster files from Arcmaps itself, I have to export

as a TIFF. That works fine, too, and again seems to have coordinates.

The question is: am I losing any data that is contained in the “invalid”

files? Do I need all three of the kinds of shapefile subfiles that seem to

work? They all have the same attribute table contents. Why would ESRI use 8

different subfiles for a “shapefile” and the NY Ortho use 4 (evidently

needed for Arcmaps) if they contain only redundant information? Am I safe

just using one of the ones that work, such as .shp and .p2, and not

worrying about the rest?

Hope that makes the question clearer.

Followup question;:

It would be lovely to just be able to import my Arcmaps work instead of

rebuilding everything. I understand SLYER is expensive. I found an open

source plugin, Mxd2Qgs, that suppsedly would import my map packages, but I

don’t understand the documentation. Suggestions?

Thanks! Glad I found this list!

Judy

–

Randal Hale

North River Geographic Systems, Inc

https://www.northrivergeographic.com

(p) 423.653.3611

(e) rjhale@northrivergeographic.com

Karsten · March 3, 2022, 9:47pm

Hi Judith,

in order to load a shape file you have to select the *.shp file e.g. if you have one shape file building you should have (as a minimum) 3 files:

building.dbf (attributes . this is the old dbase format table)
building.shp (geometries)
building.shx (index to join geometries and attributes)

in addition you could have the projection file:
building.prj

All other files you mentioned like building.cpg etc. have been produced by ArcGIS and are not read by QGIS and also not needed at all (those are for internal use in ArcGIS …)
Read about shape file here https://en.wikipedia.org/wiki/Shapefile

So there many ways to load a shape file into QGIS
1.) drag and drop the file with (windows ) explorer or your operating file manager not QGIS (only select the building,shp, the other will give you an error.
That is one correct way to load all information also the info contained in the dbf , shx and prj files ! Nothing is lost with that procedure
2.) use browser panel in QGIS and double click the shape file → will load
3.) use Menu Layer > Add Layer > Add vector layer , select desired shape file , ok → will load

Similarly, the New York State Orthographic imagery has .aux, .j2w, .jp2, and .tab

When I bring in a file, I can bring in .aux, but QGIS flags it as having a Read Block error, and .jp2, which seems to be fine, shows the data just like it looks in Arcmaps, and seems to contain coordinates. For the other file types (.j2w and .tab), I get an invalid data type message. >>>
Same thing only load the *-tif or *-jp2
option 1: drag and drop via file explorer
option 2: use Menu Layer > Add Layer > Add raster layer select desired raster file (*tif or jp2 e.g.) , ok → will load
Do not try to load *aux or such files …

The question is: am I losing any data that is contained in the “invalid” files? Do I need all three of the kinds of shapefile subfiles that seem to work? They all have the same attribute table contents. Why would ESRI use 8 different subfiles for a “shapefile”
See explanation above , really needed are shp, dbf , shx and prj , in fact all other can be safely deleted !

and the NY Ortho use 4 (evidently needed for Arcmaps) if they contain only redundant information? Am I safe just using one of the ones that work, such as .shp and .p2, and not worrying about the rest?
Exactly when you managed to load the shape and tif or jp2 and the loading correctly then you are done

It would be lovely to just be able to import my Arcmaps work instead of rebuilding everything. I understand SLYER is expensive. I found an open source plugin, Mxd2Qgs, that suppsedly would import my map packages, but I don’t understand the documentation. Suggestions?
Transferring styles between programs is difficult . If you can have someone export from ArcGIS the *.lyr styles as SLD format ( see https://en.wikipedia.org/wiki/Styled_Layer_Descriptor ) as is possible with some ArcGIS extensions then go that route (least trouble).
I could not find the Mxd2Qgs plugin so far…

Cheers
Karsten