Abstract: New requirements are arising in environments where we have higher volumes of data with high operation rates, agile development and cloud computing. In recent years, a growing number of companies have adopted various types of non-relational database, commonly referred to as NoSQL database. This reflects the growing interactivity of applications which are becoming more networked and social, driving more requests to the database where high-performance NoSQL database such as MongoDB becomes favorable. This paper attempts to use NoSQL database to replace the relational database. It mainly focuses on one of the boosting technology of NoSQL database i.e. MongoDB, and makes a comparison with MySQL and thus justifies why MongoDB is preferred over MySQL. Lastly, a method is proposed to integrate these two types of database by adding a middleware (Metadata) between application layer and database layer.