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A field that uniquely identifies record in a table is known as
- a)Candidate key
- b)Primary key
- c)Unique key
- d)Special key
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
A field that uniquely identifies record in a table is known asa)Candid...
Answer:
Candidate key:
A candidate key is a field or combination of fields in a table that uniquely identifies each record in the table. It is a potential key that can be chosen as the primary key for the table.
Primary key:
A primary key is a candidate key that is chosen to uniquely identify records in a table. It is a special type of candidate key that is used to enforce data integrity and ensure that each record in the table is unique. The primary key cannot contain null values and must be unique for each record in the table.
Unique key:
A unique key is a candidate key that is used to enforce the uniqueness of values in a column or combination of columns. Unlike a primary key, a unique key can contain null values, but the combination of values in the column(s) must be unique.
Special key:
There is no such concept as a "special key" in the context of database design or table structure. It is not a valid option to choose as the answer for this question.
Conclusion:
The correct answer to the question is A: Candidate key. The candidate key uniquely identifies records in a table and can be chosen as the primary key.
View all questions of this test
Candidate key:
A candidate key is a field or combination of fields in a table that uniquely identifies each record in the table. It is a potential key that can be chosen as the primary key for the table.
Primary key:
A primary key is a candidate key that is chosen to uniquely identify records in a table. It is a special type of candidate key that is used to enforce data integrity and ensure that each record in the table is unique. The primary key cannot contain null values and must be unique for each record in the table.
Unique key:
A unique key is a candidate key that is used to enforce the uniqueness of values in a column or combination of columns. Unlike a primary key, a unique key can contain null values, but the combination of values in the column(s) must be unique.
Special key:
There is no such concept as a "special key" in the context of database design or table structure. It is not a valid option to choose as the answer for this question.
Conclusion:
The correct answer to the question is A: Candidate key. The candidate key uniquely identifies records in a table and can be chosen as the primary key.
Most Upvoted Answer
A field that uniquely identifies record in a table is known asa)Candid...
Understanding Keys in Database Tables
In database management, identifying unique records in a table is crucial for data integrity. Several types of keys serve this purpose, and it's important to differentiate between them.
Candidate Key
- A candidate key is a field (or combination of fields) that can uniquely identify a record in a table.
- Each table can have multiple candidate keys, but only one of them can be selected as the primary key.
- For example, in a student database, both Student ID and Email can serve as candidate keys, as each can uniquely identify a student.
Primary Key
- The primary key is a specific candidate key selected to uniquely identify records.
- It ensures that no two records can have the same value for this key.
- The primary key cannot contain NULL values, ensuring complete record identification.
Unique Key
- A unique key also guarantees uniqueness for a column (or set of columns) in a table.
- Unlike primary keys, unique keys can accept NULL values, allowing for flexibility in data entry.
Special Key
- The term "special key" is not commonly used in database terminology and can refer to various concepts depending on the context.
- It does not have a standard definition in relation to identifying records.
Conclusion
While the correct answer to the question is option 'A', the term "candidate key," it is essential to understand how it relates to primary and unique keys. Candidate keys provide the foundation for record identification, while the primary key is the chosen candidate key that enforces uniqueness within the table.
In database management, identifying unique records in a table is crucial for data integrity. Several types of keys serve this purpose, and it's important to differentiate between them.
Candidate Key
- A candidate key is a field (or combination of fields) that can uniquely identify a record in a table.
- Each table can have multiple candidate keys, but only one of them can be selected as the primary key.
- For example, in a student database, both Student ID and Email can serve as candidate keys, as each can uniquely identify a student.
Primary Key
- The primary key is a specific candidate key selected to uniquely identify records.
- It ensures that no two records can have the same value for this key.
- The primary key cannot contain NULL values, ensuring complete record identification.
Unique Key
- A unique key also guarantees uniqueness for a column (or set of columns) in a table.
- Unlike primary keys, unique keys can accept NULL values, allowing for flexibility in data entry.
Special Key
- The term "special key" is not commonly used in database terminology and can refer to various concepts depending on the context.
- It does not have a standard definition in relation to identifying records.
Conclusion
While the correct answer to the question is option 'A', the term "candidate key," it is essential to understand how it relates to primary and unique keys. Candidate keys provide the foundation for record identification, while the primary key is the chosen candidate key that enforces uniqueness within the table.
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A field that uniquely identifies record in a table is known asa)Candidate keyb)Primary keyc)Unique keyd)Special keyCorrect answer is option 'A'. Can you explain this answer? for Class 8 2025 is part of Class 8 preparation. The Question and answers have been prepared according to the Class 8 exam syllabus. Information about A field that uniquely identifies record in a table is known asa)Candidate keyb)Primary keyc)Unique keyd)Special keyCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 8 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A field that uniquely identifies record in a table is known asa)Candidate keyb)Primary keyc)Unique keyd)Special keyCorrect answer is option 'A'. Can you explain this answer?.
A field that uniquely identifies record in a table is known asa)Candidate keyb)Primary keyc)Unique keyd)Special keyCorrect answer is option 'A'. Can you explain this answer? for Class 8 2025 is part of Class 8 preparation. The Question and answers have been prepared according to the Class 8 exam syllabus. Information about A field that uniquely identifies record in a table is known asa)Candidate keyb)Primary keyc)Unique keyd)Special keyCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Class 8 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A field that uniquely identifies record in a table is known asa)Candidate keyb)Primary keyc)Unique keyd)Special keyCorrect answer is option 'A'. Can you explain this answer?.
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