The table is the basic building block in database design. An attribute (or column) that uniquely identifies a particular object (or row) in the table is called:单项选择题
A
foreign key.
B
unique key.
C
primary key.
D
composite key.

Question

The table is the basic building block in database design. An attribute (or column) that uniquely identifies a particular object (or row) in the table is called:

BlackTom AI · Accepted Answer

A primary key is the attribute (or minimal set of attributes) that uniquely identifies each row in a table.

1) Relevant concepts:
- Table: collection of rows (records) and columns (attributes).
- Key: one or more attributes used to identify rows.
- Primary key: the designated attribute(s) that uniquely and unambiguously identify each record; must be unique and not NULL.
- Unique key: a constraint that enforces uniqueness on a column but is not necessarily the designated primary identifier.
- Foreign key: an attribute that references a primary key in another table to express relationships.
- Composite key: a key made of two or more attributes combined to provide uniqueness.

2) Step‑by‑step reasoning:
- The question asks for the name of the column/attribute that uniquely identifies a particular row.
- A column that guarantees uniqueness for identification is a key.
- The database term for the chosen, authoritative identifier for rows in a table is “primary key.”

3) (No numerical calculations are needed; logical deduction is used.)

4) Why “primary key” is correct:
- By definition, the primary key is the attribute (or minimal set of attributes) chosen to uniquely identify each record in a table. It enforces uniqueness and non‑nullness to ensure each row is distinct and addressable.

5) Why the other options are incorrect:
- Foreign key: used to link to a primary key in another table; it does not primarily identify rows within its own table.
- Unique key: enforces uniqueness but may allow NULLs or may not be the designated identifier; it is a constraint type, not necessarily the main identifying key.
- Composite key: describes a key composed of multiple columns; it can be a primary key if chosen as such, but the question asks for the general term for the identifying attribute — “primary key.”

Conclusion: The correct answer is “primary key.” This matches the provided answer.

The table is the basic building block in database design. An attribute (or column) that uniquely identifies a particular object (or row) in the table is called:单项选择题

类似问题

If order_id is declared as a PRIMARY KEY, which of the following are guaranteed? Choose all that apply.

什么是主键？

Inspect the following conceptual model Identify the primary key of the Store entity

Each table in a relational database has one field designated as its primary:

Which of the following best describes the purpose of a primary key?

After transforming the above ERD to a Relational Schema, what is the primary Key for patient treatment?

In a relational database, which of the following about Primary Key is FALSE

A primary unique key:

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单