For a simple task like this I would use ogr2ogr (it is in the OSGEO4W shell if you are on Windows).
To merge filename1.shp and filename2.shp into merge.shp you would do:
ogr2ogr -f ‘ESRI Shapefile’ merge.shp filename1.shp
ogr2ogr -f ‘ESRI Shapefile’ -update -append merge.shp filename2.shp -nln merge
Then just keep repeating the 2nd line for as many ...
The layer is provided as a polygon so you'll need to convert the polygons to points and calculate the XYs of each point.
Enable 'on the fly' CRS projections in Project Properties
Ensure that the Selected CRS is the CRS you want to project the data to
Add vector layer
Right click layer and "Save vector layer as..."
Select the CRS you want the layer exported ...
I think you have a few options.
1) ArcGIS online if your data are limited and you just want to get it online (they have free limited use for individuals).
2) Mapserver if you need something more robust and are more server focused.
3) Leaflet if want you want is more mobile.
But as whitebox says, it depends exactly what features of Tableau you want (want ...
There are several ways to merge vector layers in QGIS. While the ogr2ogr solution provided by Ian is perfectly viable, the need to use text commands can be a bit intimidating to the non-code oriented user (like me!). Here's another option.
The Processing Toolbox has two tools for merging vector layers. One is a core QGIS tool, the other is a SAGA tool.
Figured this out. This process should work for any shapefile held in a Postgis database, and will put it in a format that can then be plotted as a polygon in Tableau directly from the database; no mucking about importing or exporting stuff. It will create a new table containing the data in the shapefile in a format thats usable by Tableau. The more ...
The approach in the link you provide is for a different scenario. There Tableau is using built in geocoding rather than spatial data (a secret left join on your data to spatial data held in a firebird database in the install directory)
In the current release of Tableau you have to have all spatial data in a single table. So for your first part "how do i see ...
NOTE: The error is not in QGIS but in the workaround provided in this Tableau tutorial: https://community.tableau.com/docs/DOC-5831
QGIS can read the zipped school district shapefiles from TIGER without unzipping
Simply right-click the layer, choose 'Save As', and choose the Format of Keyhole Markup Language (KML).
Also ensure the output coordinate system ...
I created some videos that take you through the entire process of taking a shape file, bringing it into qgis, exporting the geometry data, converting it into Tableau format, and then loading it into Tableau.
Let me know if this helps.
Tableau has a knowledge base topic on this: Creating Tableau Polygons from ArcGIS Shapefiles.
The topic says to use ET GeoWizards tool to help prepare the shapefile, and that only free functionality from ET GeoWizards is needed. The Polygon-to-Point wizard is used, so you may be able to use the Geoprocessing tool, Feature to Point, if you have an ArcInfo ...