The most common technique that is used for design the database

Added on - 16 Sep 2019

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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. Itshows the element and their description on every level of flowing diagram. In thisfirst it shows how the data will enter into the system and how does it manipulatewithin the system while travelling through the several stages, how system storesthe 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 ofcharts it shows how the static data element logically relates among each other. Itonly show that how does our system will look like and it does not explain the flowof data, he ERD gives the elaborative description of the relation between thedata.Attributes of ERD are the table ame and the field in each table. We represent thetable name in the rectangle box, and all the field associated with that table isshown in the oval. The key identifier are used to show that a field associated withthe table is holding any key there is majorly two types of keys that are primarykey and foreign key.Relation type between two attributes can be of three type and that are one toone, one to many and many two any. One to one relationship among twoattribute represents that there could be only one entry in each table for a foreignkey, 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 manynumber of entries.
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