cicatrix

SELECT number, DENSE_RANK()  OVER(ORDER BY DIFF ASC) range_id
FROM
	(
		SELECT [number], [number] - DENSE_RANK()  OVER(ORDER BY [number] ASC) DIFF
		FROM [TestSet]
	) t
ORDER BY [number]

using (SqlConnection conn = new SqlConnection(connectionString))
{
    string sqlText = "INSERT INTO [Library] (Title, Tags, Body) OUTPUT INSERTED.[Id] VALUES(@Title, @Tags, @Body)";
    using (SqlCommand cmd = new SqlCommand(sqlText, conn))
    {
        cmd.Parameters.AddWithValue("Title", title);
        cmd.Parameters.AddWithValue("Tags", tags);
        cmd.Parameters.AddWithValue("Body", body);
                    
        try
        {
            conn.Open();
            Guid insertedGuid = (Guid)await cmd.ExecuteScalarAsync(); // <-- созданный GUID
        }
        finally
        {
            conn.Close();
        }                    
    } // using cmd
} // using conn