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Custom OData queries

Both the asset-centric OData service and the data-modeling OData service support custom queries to filter properties and retrieve specific datasets.

Custom query URLs​

Asset-centric OData service example​

To filter on a resource type property:

GET .../{resourceType}/?$filter={Filter}

Where:

  • {resourceType}: a resource type, such as Assets, TimeSeries, Events, etc.
  • {Filter}: the OData filter expression.

Data-modeling OData service example​

To filter on a view property in a data model:

GET .../{view}/?$filter={Filter}

Where:

  • {view}: the name of the view in your data model.
  • {Filter}: the OData filter expression.

Custom query examples​

Simple equality filter​

An equality filter uses the format AttributeName eq 'AttributeValue':

GET .../Assets?$filter=Name eq '23-TE-96116-04'

Data modeling filtering​

A filter applied directly to a property of a data model view:

GET .../City?$filter=iso2 eq 'MX'

Metadata filtering​

For metadata, filtering is performed on properties nested inside the metadata object:

GET .../Assets?$filter=MetaData/RES_ID eq '525283'

Combined filter​

GET .../Assets?$filter=MetaData/RES_ID eq '525283' and Name eq '23-TE-96116-04'

Using functions in filters​

OData supports functions like startswith, endswith, and contains.

For example, to filter time series where ExternalId starts with 'Sensor':

GET .../TimeSeries?$filter=startswith(ExternalId,'Sensor')

Note: Not all functions are supported for pushdown to CDF. Check the filtering capabilities of the specific resource type.

Combining multiple query parameters​

You can combine multiple query options to refine your data retrieval.

For example, to retrieve assets where Name starts with 'Pump', select only Id and Name, and order by Name:

GET .../Assets?$filter=startswith(Name,'Pump')&$select=Id,Name&$orderby=Name asc

Debugging custom queries​

  • Use separate tools: Tools like Fiddler allow you to inspect the HTTP traffic between your client and the server.
  • Check the filter syntax: Ensure that your filters are correctly formatted according to the OData specification.
  • Review supported filters: See Filter items in data models and Filtering asset-centric resource types to learn about the filtering capabilities supported by the OData services.

Limitations​

Not all OData functions and features are supported. For detailed information on supported features and limitations, refer to the individual service documentation .

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