How can MySQL query judge whether multiple field values exist at the same time

For example, registration query Do you have a cell phone number 、 mailbox 、 user name 、 The nickname is repeated ,
SELECT COUNT(nickname) FROM user where nickname=' Fruit juice '
You can't check like this 4 Time , There is a way to find out at one time 4 Does the value exist , And distinguish which exists and which does not exist