Then Allah made him rise from his sleep. When he got up, he looked at his donkey. He was surprised to see only the bones of its decaying skeleton. He wondered what had happened to his donkey. He then noted that his food was as fresh as it was when he fell asleep. He was wondering about all this when Allah asked him if he knew how long he had been asleep. He said, " for a day, or even less!" Allah then told him that he had slept for a hundred years. During this period, his perishables remained fresh by His permission, but his living animal had undergone the natural process of death and dissolution. Then Allah made his donkey also come to life in front of his eyes. Uzair acknowledged that Allah had total command over all things.
He then headed for the "ruins" of the dwellings he had seen before his "sleep" and saw that the cities had been totally rebuilt and life was bustling again. He was received by the king with great curiosity and when they heard his strange story, they said he had to be the Son of God, to have come back from amongst the dead! In Qur'an, Allah has admonished Bani Israil who had this false belief.
He is known as Ezra in Torah.
You can see details here http://islamicmobility.com/pdf/Prophet%20Uzair.pdf