mysql union选择1个不同的条件

I have a huge select, basically 3 selects glued together with 2 UNIONs. All the select columns are the same within each of my selects. The one thing that is different in every one of them is the WHERE clausule. All of them have almost the same where conditions (there is only one condition in each of them that differs from others). My statements goes like thisI have a huge select, basically 3 selects glued