How to hash passwords in MySQL?

Question

How I will make every password in my user table encrypted(md5()) except one particular row using a single query?

Answer 1

UPDATE table SET Password = MD5(Password)

I will say though that MD5 isn't a very good level of encryption and you should consider something stronger such as ENCRYPT with a custom salt. Read about it here

EDIT: Looks like the original question changed. Here's the altered query to accomodate

UPDATE table SET Password = MD5(Password) WHERE ID!=[specified index]

EDIT: Worth noting

MD5 Encryption Hacked