Chemistry, asked by pushpags856, 10 months ago

what are the different keys to create relationship in computer​

Answers

Answered by salzgeberr
2

Answer:

All-key Relations

It is possible to have a table in which every column is part of the primary key. As an example, consider a library book catalog where each book title owned by a library has a natural unique primary key: the ISBN (International Standard Book Number). Each ISBN is assigned to one or more subject headings in the library's catalog, and each subject heading is also assigned to one or more books. We therefore have a many-to-many relationship between books and subject headings. A relation to represent this relationship might be:

subject_catalog (isbn, subject_heading)

All we need to do is pair a subject heading with a book identifier and no additional data is needed. Therefore, all columns in the table become part of the primary key.

There is absolutely no problem with having all-key relations in a database. In fact, they occur whenever a database design contains a composite entity that has no relationship data. They are not necessarily errors, and you can use them wherever needed.

Explanation:

Answered by Shreyasreejith1239
1

Answer:

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Explanation:

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