Logical schema to allow access to a relational database without using knowledge of the database structure

摘要

Logical schemas are used to allow an end user the ability to access and manipulate relational database data without knowledge of the structure of the relational database. A logical schema is first created specifying which tables are available to an end user, and the relationships between columns of those tables. The logical schema defines a structure for the data fields having a master level and a plurality of detail levels. An end user may manipulate the logical schema using a graphical interface to build customized forms, reports, and queries. An end user is not required to be familiar with a database query language, such as SQL, or the structure of the relational database.