Who will win in fight between mongoose and snake?

Since childhood we have been hearing a lot about the enemity of snake and mongoose.
Have you ever wondered that who will win in a fight of snake and mongoose?

Snakes are a good meal for mongooses. So, it fights to kill the snake and the snake fights to defend itself. 
It depends upon the species of snake. If the snake is a cobra snake then the winner will be mongoose because of the fact that the poison of a normal snake cannot harm a mongoose. Where as, if the snake is a Boa Constrictor or viper then the snake will win because its poison harms mongooses very much.