RE: Embedded SQL "Nearest number" function?

I hope the OP reports back.

Apologies for not responding last Friday, due to my Mon-Thurs work-week, and my work email is not accessible from home.
Thanks to all for your consideration of this topic and suggestions.

No mention of which row to choose if there are multiple equidistant
values found. Or maybe there is a unique index on ColumnA?

Forgive if I wasn't clear, but I thought in my original post,

... If there were two rows where the difference from the
target value is the same (like if row 7 was added where ColumnA was
1560), I'd prefer the larger ColumnA value.

... covered the equidistant values scenario (where 1580 was equidistant between 1560 (row# 7) and 1600 (row# 5). I did not mention whether the values would be unique. There is no index to ensure that they would be unique.

For the purpose of simplifying my question, I presented a table that was stripped down to something much more basic than the actual table I'll be applying this to. In that, I did not consider the efficiency of the solution, because (unstated in my post) I would have the potential rows in the set to be searched limited to a dozen or so by other criteria.

The solution suggested by Eric, ...

SELECT my.*, abs( DBVAL - :TestVal ) as delta FROM MYILE my ORDER BY
delta fetch first row only

... handled the small set of rows quite elegantly. With the "ORDER BY delta, DBVAL desc" modification, I was able to ensure the desired larger value would be returned when two rows had ColumnA values equidistant from the target value. And the "fetch first row only" takes care of duplicate values of ColumnA.

Translated back to my first post, that solution is:

select a.*, abs(columnA - 1580) as delta
from mkoester/mkjunk a
order by delta, columnA desc
fetch first row only;

From the data...

ROW# COLUMNA
1 2,016
2 1,527
3 1,874
4 4,769
5 1,600
6 158
7 1,560
...the result is 1600 from Row 5, as desired.

Again, I was not concerned about what the impact would be from a huge table, and did not anticipate the more complex proposals offered. But thanks for those as well.

Appreciate the help, as always!
-- Michael