How to insert unique values ​​into a table?

Question

PHP

There is a table with coordinates
lat float
lng float
How to write an INSERT so that the data does not repeat.
Now I am able to insert non-repeating data like this
. I take all the records in PHP and take the data that needs to be inserted (they can be from 0 to 50 maximum at a time) and compare them. This option does not suit me because there can be more than a million records. Is there a way to write a more optimal INSERT ?
And if the lat lng fields are designated as UNIQUE mysql will drive itself?

Answer 1

If I understand correctly, then insert ignore will help

Answer 2

two fields one unique index and forward