如果收到x则更新列，否则更新y

Question

If I have a table with 3 columns: id,column1,column2. If i want to update column1 just when receiving "column1" parameter in URL request otherwise update column2 when receiving "column2" parameter in URL adress. Is that possible? I made that but i think that's not correct:

$sql= "UPDATE people SET 
answer_yes= '$answer_yes'+1,
answer_no='$answer_no'+1";

Thank you for helping.

EDIT: Now that is working (based on Richard Vivian answer)

    If($answer_yes==1)
{

    $sql= "UPDATE people SET answer_yes= answer_yes +1"or die(mysql_error());
    mysql_query($sql);
    }
    else if ($answer_no==0)
    {
    $sql= "UPDATE people SET answer_no= answer_no+1" or die(mysql_error());
    mysql_query($sql);
    }

Answer 1

You can create 2 SQL statement options:

If($answer_yes)
{
$sql= "UPDATE people SET answer_yes= '$answer_yes'+1"
}
else
{
$sql= "UPDATE people SET answer_no= '$answer_no'+1"
}