Câu hỏi về cơ sở dữ liệu

Creating a read-only database is a task that is ________ assigned to beginning database professionals.

• Commonly

• Always

• Never

• Seldom

Properties that describe the characteristics of entities are called:

• Attributes

• Relationships

• Entities

• Identifers

________ was adopted as a national standard by ANSI in 1992.

• SQL

• Oracle

• Microsoft Access

• DBase

Which of the following is not a restriction for a table to be a relation?

• No two rows in a table may be identical.

• The cells of the table must contain a single value.

• All of the entries in any column must be of the same kind.

• The columns must be ordered.

An attribute is a(n):

• Column of a table.

• Column of a table

• Two dimensional table

• Row of a table

When using the SQL INSERT statement:

• Rows cannot be copied in mass from one table to another only.

• Rows can be inserted into a table only one at a time only.

• Rows can be modified according to criteria only.

• Rows can either be inserted into a table one at a time or in groups.

The tuples of the relations can be of ________ order.

• Sorted

• Constant

• Any

• Same

If attributes A and B determine attribute C, then it is also true that:

• (A,B) is a composite determinant.

• B → C.

• A → C.

• C is a determinant.

Which one of the following is a procedural language?

• Query language

• Relational algebra

• Domain relational calculus

• Tuple relational calculus

Using which language can a user request information from a database?

• Query

• Compiler

• Structural

• Relational