数据库原理例题ExamplesofDatabasePrinciples.doc

数据库原理例题(Examples of Database Principles)
BR (library card number, name, unit, telephone, press press, ISBN, title, addrstandardize:
Table 3: ISBN (PK, FK), title, press (PK, FK)
Table 4: Press (PK), press address
Final:
Table 1: library card number (PK), reader's name, unit, telephone number
Table 2: library card number (PK, FK), ISBN (PK, FK), loan date
Table 3: ISBN, title, press (PK) (PK, FK)
Table 4: Press (PK), press address
A relationship between the mode of W (C, P, s, G, t, R), in which the attribute implication is: C P classroom curriculum, teachers, students s, G scores, t, R, according to the following definition of functional dependency set
: f= (eg (s, C, G (t, R). (c), t, P) r, (T, s) r}
A key relationship between the mode of W is (1), the degree of standardization of W reached the highest (2), if the keyword W is divided into s W1 (C, P model), W2 (s, G, c), W3 (s, t, R, c), the degree of standardization is W1 reached the highest (3), the highest level of W2 reached the highest level (4), W3 (5) to.
Reference answer:
(1) A (S, C), B (T, R), C (T, P), D (T, S, P)
(2飞)A, INF, B, 2NF, C, 3NF, D, 4NF
The first paradigm: to eliminate the repetition in a group, that is to say, the column stores information in other columns
The second paradigm eliminates partial dependency columns, that is to say, whether there are columns that depend on a part of the primary key
The third paradigm: removes non dependent columns, and has columns that depend on non primary keys
Such as:
Student information sheet
Student ID, name, address, city, postal code, grade, gender, course, class, course, ID, name, description, teacher, ID, teaching
Teacher's name, schedule, location, prerequisite course
If so many fields are in the same table, then the design is considered to be informal, and there is a lot of duplicate information to translate the database design
For the first paradigm, you need to divide the information into two tables and establish relationshi