<PackageReference Include="System.Data.SqlClient" Version="4.8.6" />

Microsoft.SqlServer.Server.SqlFunctionAttribute

Used to mark a method definition of a user-defined aggregate as a function in SQL Server. The properties on the attribute reflect the physical characteristics used when the type is registered with SQL Server.
namespace Microsoft.SqlServer.Server { public class SqlFunctionAttribute : Attribute { public DataAccessKind DataAccess { get; set; } public string FillRowMethodName { get; set; } public bool IsDeterministic { get; set; } public bool IsPrecise { get; set; } public string Name { get; set; } public SystemDataAccessKind SystemDataAccess { get; set; } public string TableDefinition { get; set; } public SqlFunctionAttribute(); } }