The most common technique that is used for design the database
1 Pages315 Words174 Views
Added on 2019-09-16
The most common technique that is used for design the database is DFD and ERD.A DFD is used to represent the flow of data in a system in the form of graphs. It shows the element and their description on every level of flowing diagram. In this first it shows how the data will enter into the system and how does it manipulate within the system while travelling through the several stages, how system stores the value and at every stage it shows in which direction the data flows next.The ERD will represent the static data present in the database in the form of charts it shows how the static data element logically relates among each other. It only show that how does our system will look like and it does not explain the flow of data, he ERD gives the elaborative description of the relation between the data. Attributes of ERD are the table ame and the field in each table. We represent the table name in the rectangle box, and all the field associated with that table is shown in the oval. The key identifier are used to show that a field associated with the table is holding any key there is majorly two types of keys that are primary key and foreign key.Relation type between two attributes can be of three type and that are one to one, one to many and many two any. One to one relationship among two attribute represents that there could be only one entry in each table for a foreign key, one to many represents that in one table there is one but in other table therecan be many entries of foreign key, in many to many both the table contain many number of entries.