Joining and merging data

In Quantitative Commons, multiple data sources are handled in the Dataset view, made visible by clicking the chevron icon at the top left of the application window. Data present in the current data pane is sent to the dataset view by clicking the Create snapshot icon at the bottom left of the application window. Data from databases can be sent to the dataset view by selecting the …and send to dataset view or Send all tables to dataset view option in the Load from database section. To load a file into the dataset view, it can simply be dropped in the view.

Datasets in the dataset view can be dragged around within the view. If one dataset is dropped on top of another, a popup window will appear, presenting the user with an option to merge the datasets, if they have identical structure, or to join them, if they have differing structure.

It is possible to perform left, right, inner and full joins, and also to nest one of the source tables in a column of the other one. A nested column will be expressed as a subarray if exported as XML or Json.

When loading non-flat XML or Json data with unknown schema, an option is to treat nested elements as string columns. Such a column can be made into a table in the dataset view using one of the Json/XML-column to dataset table tools, before being further processed.