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

Get the largest value similar to $val:

SELECT * FROM tab WHERE val <= $val ORDER BY val DESC LIMIT 1

Get the smallest value similar to $val:

SELECT * FROM tab WHERE val >= $val ORDER BY val LIMIT 1

Get the closest value similar to $val in either direction:

SELECT * FROM tab ORDER BY abs(val - $val) LIMIT 1