Is this the school (that) you visited the other day.
that可以换成which
This is the school (that you visited the other day,定语从句)
Is this school (the one) you visited the other day?
the one 不能换成which或者that
换成肯定句：This school is the one you visited the other day.
缺了THEONE句子就不完整了
This school is (that you visited the other day,表语从句,但意思不通）.