This article is relevant to entity models that utilize the deprecated Visual Studio integration of Telerik Data Access. The current documentation of the Data Access framework is available here.
Microsoft introduced the sql_variant data type in SQL Server 2000. You can use the sql_variant to store data of an unspecified or inconsistent type. Or to store data of almost any SQL Server data type. This is very useful for an input parameter for a stored procedure that can handle many different data types, or a column in a table with heterogeneous data.
More information about the sql_variant data type could be found here.
Telerik Data Access provides support for the sql_variant data type. In order to use such a column, the column needs to be mapped to a persistent field of type object.