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.
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Chapter 3 Solutions
Database Systems: Design, Implementation, & Management
- What is meant by data archiving? Why is this an important consideration when operating a database?arrow_forwardDo the tables exhibit referential integrity? Answer yes or no, and then explain your answer. Write NA (Not Applicable) if the table does not have a foreign key. FIGURE P3.17 THE CH03_TRANSCO DATABASE TABLESarrow_forward
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