Firebase uses what is known as a NoSQL database for storing data in a Realtime Database. As the name suggest this means that data is not stored in the tables and rows found in relational database management systems (RDBMS) such as Oracle Database or Microsoft SQL Server.
Read moreDoes Firebase have a SQL database?
Firebase is a real-time object store. It is not a SQL database and is not intended to be a replacement for one. It completely lacks mechanisms such as JOINs, WHERE query filters, foreign keys, and other tools relational databases all provide. … But any attempt to treat it “like” a SQL replacement is going to fail.
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