Think of the small database we used in our lab exercise - Products and Suppliers. Briefly describe how this database observes any two of the four design principles outlined above.
Ans as below:
A database management system (DBMS) is a special type of software for creating, organizing and assessing data from a database. It is a centralization and management of data which have a single, consistent source form all their data needs. The most important feature of the database is its ability to separate the logical and physical views of data.
Access is a relational database management system. In a relational database, you divide your information into separate, subject-based tables. You then use table relationships to bring the information together as needed.
From the above example, we entry the data in tables made up of one or more columns. Each table has a special field called the primary key which contains a unique value for each record. We divide the product and supplier table separately, the divides information into subject-based tables is to reduce redundant data. The data stored in each column must be of a single data type, such as text, character, this can protect the data more accuracy and integrity.
There have two principles for the relational database, duplicate information, correctness and completeness of information which is very important and we can't make any mistakes on it. Otherwise the reports will contain incorrect information.
As the unique record have to be retrieved, updated and sorted, the column of the data must be uniquely indentifies.
We select the fields to be included in the report. From the Product table, choose Product Category, Product Name, Selling Price, Quantity on Hand and Reorder Level. From the Supplier table, choose Company Name - this is the name of the supplier for that product.
Accommodates the data processing and reporting – using database can get the report by simply sort the information that you need. From our exercise, we group the report according to Product Category and sort the data in each product category by Product Name. At last we choose a layout and page orientation for the report as needed.
Access is a relational database management system. In a relational database, you divide your information into separate, subject-based tables. You then use table relationships to bring the information together as needed.
From the above example, we entry the data in tables made up of one or more columns. Each table has a special field called the primary key which contains a unique value for each record. We divide the product and supplier table separately, the divides information into subject-based tables is to reduce redundant data. The data stored in each column must be of a single data type, such as text, character, this can protect the data more accuracy and integrity.
There have two principles for the relational database, duplicate information, correctness and completeness of information which is very important and we can't make any mistakes on it. Otherwise the reports will contain incorrect information.
As the unique record have to be retrieved, updated and sorted, the column of the data must be uniquely indentifies.
We select the fields to be included in the report. From the Product table, choose Product Category, Product Name, Selling Price, Quantity on Hand and Reorder Level. From the Supplier table, choose Company Name - this is the name of the supplier for that product.
Accommodates the data processing and reporting – using database can get the report by simply sort the information that you need. From our exercise, we group the report according to Product Category and sort the data in each product category by Product Name. At last we choose a layout and page orientation for the report as needed.
In conclusion DBMS can enhance the operation performance by increase data independence, minimize storage redundancy and increase data integrity.
That's right. Our small database has two tables - for Products and Suppliers. This shows that our data has been organized by Subject, because each table only contains information about one specific subject.
回覆刪除We also used the Report Wizard to retrieve and combine data from the tables in a more meaningful way (e.g. selecting only certain fields, sorting, grouping them, arranging the layout). This helps us with our data processing and reporting needs as well.