[MySQL] Practice six relational data theory and database design

main content

1. Possible problems with a bad relationship model;
2. Definition of functional dependencies and three types of functional dependencies: complete, partial, transitive
3. Paradigm and judgment of 1NF/2NF/3NF/BCNF
4. schema decomposition
5. Basic steps of database design
6. Conceptual Design (ER Diagram)
7. Logical model (method of converting ER diagram to logical model)

practice questions

1. Multiple choice questions

1. When analyzing database requirements, the meaning of the data dictionary is ( D ).
   A．A collection of attributes and file names involved in the database
   B. The collection of letters, characters and Chinese characters involved in the database
   C. The collection of all data in the database
   D. A collection of descriptions of data streams, data items, and files involved in a database
2. The following is not part of the requirements analysis phase of the work is ( B ).
   A．Analyze user activity
   B. Create ER diagram
   C. Create a data dictionary
   D. Create a data flow diagram
3. The dataflow graph is in the database (