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Optional interpolation variables

Each time I create a base view over a JSON data source with interpolation variables, denodo asks me to provide all of the variables. But what if the API does not support the combination of all the variables together? E.g. there is `external_id` and `local_id` and the API gives an error if you provide them both. How can I make interpolations optional _before_ creating a base view? Or how to explicitly set them to an empty string upon base view creation?
Interpolation Variables Base view Create Base View
user
15-06-2020 10:14:26 -0400

3 Answers

Hi ​ When I create base view over a data source that has interpolation variables, the Tool will display a dialog to enter the value of these variable. It is mandatory to provide sample value for the parameters defined as interpolation varaiable, because the Server will use these values to query the source and calculate the schema of the new base view. You can add one or more interpolation variables when creating a data source and all the The created base view will have a field for each interpolation variable. ​ For more information, you can have a look at the section [Paths and Other Values with Interpolation Variables](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/creating_data_sources_and_base_views/path_types_in_virtual_dataport/path_types_in_virtual_dataport#paths-and-other-values-with-interpolation-variables) of the Virtual DataPort Administration Guide. ​ Hope this helps!
Denodo Team
 Edited on: 16-06-2020 23:38:29 -0400
Thank you for your answer, but it did not solve my issue. I understand denodo needs parameters to query the API to create a schema. The API I use has some mutually exclusive params, so I cannot provide them all together or else the response would be empty and the schema wrong. As a workaround, can I somehow provide an empty string as a parameter? My current workaround is to only add some params, then ceate a base view, then add the rest of the params via VQL — very inconvinient.
user
16-06-2020 09:08:49 -0400
Hi, I was able to use an **empty string (' ')** as the value of the interpolation variable to create a base view over a JSON data source with the interpolation variable. You can give any possible values as it is mandatory to give value for the view creation. For more information, you can have a look at the document [JSON Sources](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/creating_data_sources_and_base_views/json_sources/json_sources#json-sources) of the Virtual DataPort Administration Guide. If you are a valid support user, then you can raise a support case in [Denodo Support Site](https://support.denodo.com/) so that our support team can help you. Hope this helps!
Denodo Team
17-06-2020 08:14:12 -0400
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