how to get nearest value from database in mysql

Question

I am using mySQL and CodeIgniter. I have some floating point numbers in my database such as

• 8.3456
• 8.5555
• 4.5556

Answer 1

(
select   *
from     table
where    value >= $myvalue
order by value asc
limit 1
)
union
(
select   *
from     table
where    value < $myvalue
order by value desc
limit 1
)
order by abs(value - $myvalue)
limit 1

This may look counter-intuitive but the speed will be greater than the other queries shown so far.

This is due to the fact that a greater than and less than query is quicker.

Then doing an ABS on two values is nothing.

This will give you the quickest return in a single query I can think of.

Doing an ABS on a whole table will be slow as it will scan the whole table.