73 lines
3.5 KiB
Markdown
73 lines
3.5 KiB
Markdown
Sometimes your data is not as simple as a normal table, or the sort of
|
|
statements that you want to do varies on each row. This document
|
|
explains how to work around these cases.
|
|
|
|
## Hierarchical data {#hierarchical-data}
|
|
|
|
Sometimes your source provides data in a structured format, such as XML,
|
|
JSON or RDF. OpenRefine can import these files and will convert them to
|
|
tables. These tables will reflect some of the hierarchy in the file by
|
|
means of null cells, using the [records mode](/manual/exploring#rows-vs-records).
|
|
|
|
The Wikibase extension always works in rows mode, so if we want to add
|
|
statements which reference both the artist and the song, we need to fill
|
|
the null cells with the corresponding artist. You can do this with the
|
|
**Fill down** operation (in the **Edit cells** menu for this column).
|
|
This function will copy not just cell values but also reconciliation
|
|
results.
|
|
|
|
## Conditional additions {#conditional-additions}
|
|
|
|
Sometimes you want to add a statement only in some conditions.
|
|
|
|
The workflow to achieve this looks like this:
|
|
- Use facets to select the rows where you do not want to add any
|
|
information;
|
|
- Blank out the cells in the column that contain the information you
|
|
want to add. If you do not want to lose this information, you can
|
|
create a copy of the column beforehand;
|
|
- Remove your facets to see all rows again;
|
|
- Create a schema using the column you partially blanked out as
|
|
statement value.
|
|
|
|
## Varying properties {#varying-properties}
|
|
|
|
Sometimes you wish you could use column variables for properties in your
|
|
schema. It is currently not possible, first because we do not have a
|
|
reconciliation service for properties yet, but also because allowing
|
|
varying properties in a statement would mean that these properties could
|
|
potentially have different datatypes, which would break the structure of
|
|
the schema.
|
|
|
|
If you only want to use a few properties, there is a way to go around
|
|
this problem. For instance, say you have a first column of altitudes and a
|
|
second column that indicates whether you should add it as
|
|
[operating altitude (P2254)](https://www.wikidata.org/wiki/Property:P2254) or as
|
|
[elevation above sea level (P2044)](https://www.wikidata.org/wiki/Property:P2044).
|
|
|
|
Create a text facet on the first column. Filter to keep only the
|
|
*altitude* values. Add a new column based on the second column, by
|
|
keeping the default expression (`value`) which just copies the existing
|
|
values. Then, select the *maximum operating altitude* value in the facet
|
|
and do the same. Reset the facet, you should have obtained two new columns
|
|
which partition the original column. You can now create a schema which adds
|
|
two statements, with values taken from those columns. Since blank values are
|
|
ignored, exactly one statement will be added for each item, with the desired property.
|
|
|
|
## Adapting to existing data on Wikibase {#adapting-to-existing-data-on-wikibase}
|
|
|
|
Sometimes you want to create statements only if there are no such
|
|
statements on the item yet. Here is one way to achieve this:
|
|
|
|
- first, retrieve the existing values from Wikidata first, using the
|
|
**Edit columns** → **Add columns from reconciled values** action;
|
|
- second, create a *facet by null* on the newly created column that
|
|
contains the information you want to control against;
|
|
- select the non-null rows (value **false**);
|
|
- clear the contents of the column where your source values are
|
|
(**Edit cells** → **Common transformations** → **To null**).
|
|
|
|
You can now construct your schema as usual - null values will be ignored
|
|
when generating the statements.
|
|
|