Keys and Relationships in Databases

What is a Primary Key?

• A unique identifier for each record in a database table.

• A type of column that holds the primary key value.

• A method to connect different tables.

• A way to ensure data redundancy.

What is an ID Field?

• A unique identifier for each record.

• A type of column that holds the primary key value.

• A method to connect different tables.

• A way to ensure data redundancy.

Table Relationships

• Define how different tables are connected.

• Ensure data redundancy.

• Provide unique identifiers.

• Maintain data integrity.

The One-to-One Relationship

• Each record in one table corresponds to exactly one record in another table.

• One record in one table can relate to multiple records in another table.

• Multiple records in one table can relate to multiple records in another table.

• None of the above.

The One-to-Many Relationship

• Each record in one table corresponds to exactly one record in another table.

• One record in one table can relate to multiple records in another table.

• Multiple records in one table can relate to multiple records in another table.

• None of the above.

Advantages of Using Keys and Relationships

• Ensures consistency and accuracy.

• Reduces the duplication of data.

• Allows for faster access to specific information.

• All of the above.