SQL Server: How to update a cell value at position (x,y)

Question

SQL Server Question:

I have a table with appx. 1000 already existing rows, and 5 columns

How can I update the value at row Y in column ?

I don't have any keys or conditions for the where.

Answer 1

WITH    q AS (
        SELECT  m.*, ROW_NUMBER() OVER (ORDER BY column) AS rn
        FROM    mytable m
        )
UPDATE  q
SET     mycol = 'newvalue'
WHERE   rn = @Y

Note that in SQL there is no concept of implicit row order.

There is no n'th row unless you define the ordering condition (column in example above).

In this table:

col1 col2
1    2
2    1

, the row (1, 2) is first when ordering by col1, and second when ordering by col2.

Answer 2

First, you add a primary key, whether you already have a candidate key (possibly even a composite key) or choose to use a surrogate key. You can then use that as your criteria in your where clause.