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本帖最后由 rifathasan2005 于 2024-9-22 17:24 编辑
Data Flow Diagram (DFD) Example: A Visual Representation of Data Movement A Data Flow Diagram (DFD) is a graphical tool used to illustrate the flow of data through a system. It provides a high-level view of the processes involved, the data inputs and outputs, and the data stores used. Example: An Online Bookstore Scenario: A simple online bookstore system. DFD: Opens in a new window Data Flow Diagram for an online bookstore Whatsapp Number Explanation: External Entity: Represents entities outside the system that interact with it. In this case, the customer and the supplier are external entities. Process: Represents the activities or transformations performed on data.
For example, the processes "Search for Books," "Place Order," and "Process Order" are shown in the diagram. Data Store: Represents a repository of data. In this case, the "Book Inventory" and "Customer Information" are data stores. Data Flow: Represents the movement of data between entities, processes, and data stores. The arrows indicate the direction of data flow. Key Components of a DFD Context Diagram: The highest-level DFD, showing the system's boundaries and its interacts with external entities.
Level 0 DFD: A detailed DFD that breaks down the system into its major processes and data flows. Level 1 DFD : Further decomposes the processes from the Level 0 DFD into more detailed subprocesses. Data Flow Diagram (DFD) Example: A Visual Representation of Data Movement A Data Flow Diagram (DFD) is a graphical tool used to illustrate the flow of data through a system . It provides a high-level view of the processes involved, the data inputs and outputs, and the data stores used. Example: An Online Bookstore Scenario: A simple online bookstore system. DFD: Opens in a new windo Data Flow Diagram for an online bookstore Explanation: External Entity: Represents entities outside the system that interact with it. In this case, the customer and the supplier are external entities. Process: Represents the activities or transformations performed on data. For example, the processes "Search for Books," "Place Order," and "Process Order" are shown in the diagram. Data Store: Represents a repository of data. In this case, the "Book Inventory " and "Customer Information" are data stores. Data Flow: Represents the movement of data between entities, processes, and data stores
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