How to merge multiple layers to one layer?

Question

I've imported several shapefiles which where exported from an Mapinfo .tab. Several tab files are imported resulting in 20+ layers. Afterwards I want to export it to geoJSON; but I'm reluctant for selecting each layer and exporting it.

Is there a way to merge all the layers to one?

Answer 1

you can use MMqgis tools for merging...

The merge layers tool merges features from multiple layers into a single shapefile and adds the merged shapefile to the project. One or more layers are selected from the "Select Source Layers" dialog list box and an output shapefile name is specified in the "Output Shapefile" dialog field.

Merged layers must all be the same geometry type (point, polygon, etc.). If the source layers have different attribute fields (distinguished by name and type), the merged file will contain a set of all different fields from the source layers with NULL values inserted when a source layer does not have a specific output field.

i hope it helps you...

Answer 2

MMgis was found under the 'Plugins' Menu in QGIS 1.8.0 Lisboa. Just in case people do not find it under the 'Vector' menu. I am not sure it this can be changed by the user.

Answer 3

You can use the 'merge shapefiles to one' function under the menu vector|Data management tool. You can merge all files in the input directory or select specific files in the input directory.

The same applies as for MMqgis tool: merged layers must all be of the same geometry type. Also, if the source layers have different attributes fields, the merged file will contain all fields, but with NULL values inserted when a source layer does not have a specific field.