関連ワード:  what is relational database explain    what is relational database explain with example    what is relational database explain its key components    what is relational database model explain    what is relational database design explain with example    what is relational database management system explain    what is relational database model (rdbms) explain    what is a relational database query explain with an example    what is relational database explain the purpose of creating database    explain what is meant by relational database