Question

3
Multiple choice select three correct answers. .
1) Valid relationships in RDBMs are
a) one to one
b)one to two
c) one to many
d) many to two
e) many to many
f) one to three​

Answer 1

Answer:

A C And E

Explanation:

In a relational database, a one-to-one relationship exists when one row in a table may be linked with only one row in another table and vice versa. It is important to note that a one-to-one relationship is not a property of the data, but rather of the relationship itself.

In a relational database, a one-to-many relationship exists when one row in table A may be linked with many rows in table B, but one row in table B is linked to only one row in table A. It is important to note that a one-to-many relationship is not a property of the data, but rather of the relationship itself.

A many-to-many relationship occurs when multiple records in a table are associated with multiple records in another table. Relational database systems usually don't allow you to implement a direct many-to-many relationship between two tables. ... Consider the example of keeping track of invoices.

Answer 2

Answer: a, c, and e are correct answers.

Concept:

A relational database stores various data sets in the form of tables, records, and columns. It's utilized to establish a well-defined relationship between database tables so that relational databases may be stored conveniently.

Find:

The valid relationships in RDBMS.

Solution:

The valid relationships in RDBMS are:

• One to One Relationship (1 : 1): It's a relationship between two tables in which a single row of the first table can only be associated with one and only one record in the second table. Similarly, each row of the second table can be associated with any one row of the first table.
• One to Many Relationship (1 : N): This type of relationship is used to link two tables together. The rows of the first table can be associated with one or more rows of the second table, but the rows of the second table can only be related to the first table's only row. A many-to-one relationship is another name for it.
• Many to Many Relationship (N : N): A relationship between two tables is created through many to many relationships. Each record in the first table can be related to any record in the second table (or none at all). Similarly, each record in the second table can be linked to several records in the first.

Hence, a, c, and e are correct answers.