The OData service should return everything if the $select query parameter is not specified by default. In certain cases, this functionality can be set to true, allowing retrieval of every column from the specified dataset. This applies specifically to SQL queries.

Data Type

bool

Default Value

false

Remarks

When ExpandAsterisk is true, all columns reported as queryable from the service will be included in the $select query parameter.

For example:

SELECT * FROM Items

All columns will be listed in projection.

SELECT col1,col2, ... , coln FROM Items

This property helps you quickly retrieve object graphs and makes debugging easier. However, it can create large data loads and costly queries when there is a lot of deep nesting. For OData entities labeled as OpenType, the Returns columns are not defined in the metadata document and do not appear in the table definition.
Therefore, when the ExpandAsterisk property is set to true, these columns will not be automatically appended to the $Select query parameter unless they are explicitly requested.