Insert values into table

[Alex_B]

I am having slight problem with insertion.
What I am trying to do is insert certain values into database table, but would like new values to be inserted only if there are no such values already exist in that table.

The problem is that I do not see fast solution. The slower way is to get the value then check if that value exist in that table

SELECT count FROM table where data="..."

if count > 0

than do not insert

else

insert into .....

That means I will make two requests each time I am trying to insert the value. That seems like waste of time and resources.
Is there a single query that will check against the table values and do insert only if the value does not exist there?

[YappyDog]

What you're trying to do cannot be done in one query.

The only other way to do it would be to put some sort of database constraints on the table to make sure the values are unique. Duplicate entries would be rejected, but your code would need to handle those errors.

[Alex_B]

That is what I was afraid of. Thank you though