PHP Protocol Buffer to MySQL (and back!) bridge
http://stuporglue.org/protocol-buffer-to-mysql-bridge/
Protobuf ORM
https://github.com/rene-post/protobuf-orm
one way: sql-protobuf
https://www.npmjs.com/package/sql-protobuf
MySQL-protobuf
https://github.com/google/mysql-protobuf/wiki
proto-sql
https://github.com/commandus/proto-sql