MySQL three ways to avoid repeated insertions

In development, we often encounter such requirements, if the inserted data does not exist to insert the presence of the update ( or do not do anything ). The MySQL insert provides this functionality without the need for us to do the processing on our own business logic code. Directly with the functionality provided by MySQL. Click on the link below to see how to use

Http://www.cnblogs.com/zeroone/archive/2012/04/18/2454728.html

http://www.sifangke.com/2013/05/mysql-insert-sql/

MySQL three ways to avoid repeated insertions