こんなwhere句の作り方

うーん。。。

>> where = String.new
=> ""
>> where << hoge= i == 0 ? " where " + "hoge = fuga" : " and " + "hoge = fuga"
=> " where hoge = fuga"
>> where << hoge = i == 1 ? " where " + "hoge = fuga" : " and " + "hoge = fuga"
=> " where hoge = fuga and hoge = fuga"
>> where << hoge = i == 1 ? " where " + "hoge = fuga" : " and " + "hoge = fuga"
=> " where hoge = fuga and hoge = fuga and hoge = fuga"

i = 0 なら左がhogeに代入されてwhereに追加される。みたいな。