SQL Server DBLlink to oracle将数字作为字符串返回

I have an Oracle database containing my data and an SQL Server database getting the data from Oracle through DBLink. Problem is - all numbers from the Oracle tables are accepted at the SQL Server as nvarchar. As a result, when i try to filter the query in the SQL Server with some_number_field = 0 i get: "Conversion failed when converting the nvarchar value '3.141' to data type int." This also happens if i try to select "some_number_field * 1" or similar expressions. Any idea ?I have an Oracle database containing my data an