sql statement with not null in as3

Am trying to pass a not null value to sqlite parameter in as3 in adobe air for desktop, here is the sample of code:

stat.text = "SELECT * FROM people, WHERE gender = @gender AND year = @year AND month = @month";
stat.parameters["@gender"] = genderBox.value;
stat.parameters["@year"] = year.text;
stat.parameters["@month1"] = month.text;

where genderBox is a combobox with 2 values of course male and female and the others are just textboxes. i want to make the genderBox having 3 values the third one is Both males and females so when the user select both the statment select both the males and females i want it to pass something like not null value and select everything from that column but choose the other columns month and year