
Primary Key:
A Primary Key in a
Example:
Students in Universities are assigned a unique registration number.
Therefore, in a STUDENT database table, the attribute “reg_no” acts as primary key.
Foreign Key:
Foreign Key is a column in a relational database table which provides a relation between two tables. It provides a cross reference between tables by pointing to primary key of another table.
Example:
In STUDENT database table, the attribute “reg_no” acts as primary key and in COURSE database table in which the student selects his or her course, the same “reg_no” acts as foreign key for the STUDENT table.
Many to One Relationship:
When more than one record in a database table is associated with only one record in another table, the relationship between the two tables is referred as many to one relationship. It is also represented as M: 1 relationship.
One to Many Relationship:
When one record in a database table is associated with more than one record in another table, the relationship between the two tables is referred as one to many relationship. It is also represented as1: M relationship. This is the opposite of many to one relationship.
CROW FOOT ERD:
The Crow Foot ERD is an Entity Relationship Diagram which is used to represent the cardinalities present in the basic ER diagram. It is used to represent the relationships present between two tuples or tables present in the database.

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Chapter 3 Solutions
Database Systems: Design, Implementation, Management, Loose-leaf Version
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- The assignment here is to write an app using a database named CIT321 with a collection named students; we will provide a CSV file of the data. You need to use Vue.js to display 2 pages. You should know that this assignment is similar, all too similar in fact, to the cars4sale2 example in the lecture notes for Vue.js 2. You should study that program first. If you figure out cars4sale2, then program 6 will be extremely straightforward. It is not my intent do drop a ton of new material here in the last few days of class. The database contains 51 documents. The first rows of the CSV file look like this: sid last_name 1 Astaire first_name Humphrey CIT major hrs_attempted gpa_points 10 34 2 Bacall Katharine EET 40 128 3 Bergman Bette EET 42 97 4 Bogart Cary CIT 11 33 5 Brando James WEB 59 183 6 Cagney Marlon CIT 13 40 GPA is calculated as gpa_points divided by hrs_attempted. GPA points would have been arrived at by adding 4 points for each credit hour of A, 3 points for each credit hour of…arrow_forwardI need help to solve the following case, thank youarrow_forwardhi I would like to get help to resolve the following casearrow_forward
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