Join Gordon Luckett for an in-depth discussion in this video Understanding types of vector data in QGIS, part of Learning QGIS.
- Vector data, meaning data such as points, lines, and polygons, are extremely important in QGIS. The bulk of your work will be done using this type of data. Let's look at QGIS to see what types of vector data I can use. Under Layer, under Add Layer, you can see Add Vector Layer but there's other Vector Layers you can add such as a PostGIS Layer, SpatiaLite Layer, MSSQL Server Spatial Layer, Oracle Spatial Layer, as well as a WFS Layer, even a Delimited Text layer is available.
Under the Add Vector Layer, let's choose that. Right away, you see a File Source type. So when you pick the Browse button, under All Files, you'll see a list of the supported vector base data sets. From the GDAL FileHandler types, Arc/Info Coverages, Atlas BN, DXF, Comma Separated Values, Shapefiles all the way down to things such as GML, KML and even VRT, Virtual Datasource types.
There are lot of vector base data types in here that you can choose from. These are all from the File base. Now let's just cancel this for a moment. So that's File base vector. Let's look at Directory base. If I pick Type, you can see there's UK, NTF2. There's U.S. Census types. There's the OpenFile Geodatabase as well as a Binary Coverage. So what we have here are file Geodatabases, Binary Coverages, TIGER/Line and NTF.
These are folders that contain all the vector data. Not at one single file like a shapefile or a TAB file but these are folders that contain all the data. So that's what the Directory base file type is for. Under Database, this is where we get Oracle Spatial as your personal Geodatabase which is an access file, Microsoft SQL Server, and others like PostgreSQL and MySQL. Of course we can connect to data using regular ODBC. If you connect to a database or a table that has no Geographic data within it, that's okay because we can still use that tabular data for our reports and for plotting.
Finally, there's the Protocol. This one right now is only GeoJSON. So we have a URL or URI where the GeoJSON is streaming from. We can actually put it in there. In this case, I have one. Let's paste it in. At nanaimo.ca/crimereporting/ api/incidents. I put a question mark and put format=geojson. This will get all the crime incidents in GeoJSON format streaming right into my QGIS. That's what the URL is.
That URL again is nanaimo.ca/crimereporting/ api/incidents?format=geojson. If I open this, you'll see that vector data will stream right into QGIS. So why the ray of supported vector types such as shapefiles and SQLite? Make QGIS, an extremely useful tool for mapping and analysis.
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