If you need to convert/cast a database integer field to an nvarchar on a Microsoft SQL Server, you should use the convert function. In this example we cast the number 4343 to an nvarchar:

	convert(nvarchar(255), 4343)

Example to convert an int field (field_int) to a nvarchar field:

SELECT field_int,
	convert(nvarchar(255), field_int) as field_as_nvarchar
FROM [TEST].[dbo].[TestTable]

Result from the query: