問87
頻出度★★★
E-R 図に関する記述として, 適切なものはどれか。
平成29年度 春期 ITパスポート試験 問87
テクノロジ系データベース › データベース設計
This question's explanation and your answers so far.
解説
問 87
Incorrectア
What represents the algorithms of structured programming is a flowchart and other diagrams that show program structure, not a description of an E-R diagram. An E-R diagram represents the relationships between data, not a program’s algorithm.
Incorrectイ
Estimating the duration of tasks, performing scheduling, and managing the work process is done with schedule-management techniques such as an arrow diagram (PERT chart) or a Gantt chart, which have nothing to do with an E-R diagram.
Incorrectウ
Representing algorithms such as processing procedures with diagrams is the role of a flowchart. An E-R diagram does not represent an algorithm; it is a diagram that expresses the structure of data and the relationships between data.
- エ
正解 An E-R diagram (Entity-Relationship diagram) is a diagram used in database design. It represents the objects to be managed as “entities” and links the “relationships” between entities with lines, thereby expressing the relationships between data. Therefore, choice エ, which states “In designing a database, it represents the relationships between data,” is correct.
ここがポイント
- An E-R diagram is a diagram for database design that expresses the relationships between data using entities and the relationships between those entities.
- The point being tested is not to confuse diagrams that serve different purposes: algorithms are represented by flowcharts, while schedule and process management uses arrow diagrams or Gantt charts.
用語