SQL PRIMARY KEY and CHECK Constraints

Play an AI-generated podcast conversation about this lesson

What is the purpose of the DEFAULT clause in a CREATE TABLE statement?

To enforce referential integrity between tables
To create a unique index on a column
To specify the primary key of a table
To define a default value for a column when no value is specified (correct)

What type of expression can be used to specify a default value in a DEFAULT clause?

A stored procedure or a function
A constant, a built-in function, or a mathematical expression (correct)
A SELECT statement or a subquery
Only a constant value

Where is the DEFAULT clause specified in a CREATE TABLE statement?

Within the declaration of the column, together with the data type and other column properties (correct)
At the end of the CREATE TABLE statement, after the definition of all columns
In the ALTER TABLE statement, when modifying the column
In a separate statement, after the CREATE TABLE statement

What happens if you omit the DEFAULT keyword when creating a default definition in a CREATE TABLE statement?

The database engine assigns an implicit name for the default (A) Signup and view all the answers

What is the purpose of the CONSTRAINT option in a CREATE TABLE statement when creating a default definition?

To assign a name to the default constraint (D) Signup and view all the answers

Can a default value be specified for a column that has a PRIMARY KEY constraint?

Yes, and the default value is ignored if a value is specified during an INSERT operation (A) Signup and view all the answers

What happens when a default value is specified for a column and a value is also specified during an INSERT operation?

The specified value is used, and the default value is ignored (A) Signup and view all the answers

Can a default value be specified for a column that has a FOREIGN KEY constraint?

Yes, and the default value is ignored if a value is specified during an INSERT operation (C) Signup and view all the answers

What is the main benefit of using a default value for a column?

It simplifies data entry by providing a default value when no value is specified (D) Signup and view all the answers

What is the primary function of an index in a relational database?

To allow efficient access to data stored on a disk (C) Signup and view all the answers

What type of database object is derived from one or more base tables?

View (B) Signup and view all the answers

What is the purpose of the FOREIGN KEY constraint in the works_on1 table?

To create a relationship between the employee and project tables (D) Signup and view all the answers

What is the result of deleting a parent table row that has a related row in the works_on1 table?

The related row in works_on1 is deleted (C) Signup and view all the answers

What is the purpose of a stored procedure in a relational database?

To execute a sequence of statements written in Transact-SQL (C) Signup and view all the answers

What is the result of updating a parent table row that has a related row in the works_on1 table?

The related row in works_on1 is updated (D) Signup and view all the answers

What are the two types of database objects?

Physical and Logical (C) Signup and view all the answers

What is the first database object that needs to be created?

Database (D) Signup and view all the answers

What type of databases can an authorized user create?

User databases (A) Signup and view all the answers

What is managed by the Database Engine?

Both system and user databases (B) Signup and view all the answers

What is an example of a logical object?

Table (D) Signup and view all the answers

What are the system databases generated during the installation of the database system?

tempdb, model, and msdb (D) Signup and view all the answers

What is the maximum size of a database name in SQL Server?

128 characters (B) Signup and view all the answers

What is the purpose of the PRIMARY option in the CREATE DATABASE statement?

To specify the first file that contains system tables and other important internal information (D) Signup and view all the answers

SQL PRIMARY KEY and CHECK Constraints

Choose a study mode

Podcast

Questions and Answers