ODBC Driver for OData

Build 20.0.7654

Supports Expand

Whether you need to specify the base entity's key to query navigation property views.






This connection property is primarily used with limited OData APIs; it determines whether navigation properties can be retrieved from the base entity set. In OData, navigation properties link a base entity to a related entity or a collection of related entitites.

For more on navigation properties, see データモデル.

Working with Limited APIs

In OData, the $expand parameter is used to expand specified navigation properties when requesting data from a given entity set. In SQL, this makes it possible to execute a SELECT * to a navigation property view.

If $expand is not supported, a different request must be made to retrieve a navigation property, one that specifies the primary key of the base entity set. This API restriction is reflected in SQL: You will need to specify the base entity's primary key in the WHERE clause.

For example, consider two entities with a one-to-many relationship in the Northwind sample service, Categories and Products. In OData, the Products associated with a given Category could be represented as a navigation property on the base Category entity set. The 本製品 models the Products navigation property as a Categories_Products view.

If $expand is not supported, use a query like the following to this view:

SELECT       * 
FROM         Categories_Products
WHERE        (Categories_CategoryID = 1)

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Build 20.0.7654