Of course, primary keys are never defined directly against views in a commercial relationaldatabaseenvironment.
当然，从来不直接对商业关系数据库环境中视图定义主键。
2
It provides a rich environment with forms and reports language for easy development of relationaldatabase applications.
它提供一个功能丰富的环境，包括表单和报告语言，可以轻松地开发关系数据库应用程序。
3
Database design is crucial to effectively implement a relationaldatabase. In this course we discuss how to model data, database construction, and developing a database in a business environment.