SQL Find difference between previous and current row

Question

I am trying to find the difference between the current row and the previous row. However, I am getting the following error message:

The multi-part id

Answer 1

I don't think you need the partition by statement:

WITH CTE AS (
      SELECT ROW_NUMBER() OVER (ORDER BY columnOfNumbers) as ROW,
             columnOfNumbers
      FROM tableName
     )
SELECT a.columnOfNumbers, a.columnOfNumbers - b.columnOfNumbers
FROM CTE a LEFT JOIN
     CTE b
     ON a.ROW = b.ROW + 1;

If you do need it, you should put in a column name as opposed to a table name.