SQL Commands and Concepts

What type of language is SQL primarily considered to be?

• Procedural

• Object-Oriented

• Declarative

• Functional

Which of the following is NOT a primary function of SQL?

• Querying data

• Manipulating data

• Defining data structures

• Creating graphical user interfaces

In the SQL query `SELECT population FROM world WHERE name='Germany'`, what is the purpose of the `WHERE` clause?

• To specify the table from which data is retrieved.

• To define the columns to be displayed in the output.

• To filter records based on a specified condition.

• To sort the results in a particular order.

What does the asterisk (*) symbol signify when used in a `SELECT` statement (e.g., `SELECT * FROM table_name`)?

• It selects only the primary key column.

• It indicates that no columns should be selected.

• It selects all columns from the specified table.

• It is used for mathematical operations on columns.

To add a new country named "Atlantis" with continent "Oceania" and population 500000 to the 'world' table, which SQL command is correct?

• INSERT INTO world VALUES ("Atlantis", "Oceania", 500000)

• INSERT INTO world (name, continent, population) VALUES ("Atlantis", "Oceania", 500000)

• ADD RECORD TO world (name="Atlantis", continent="Oceania", population=500000)

• CREATE NEW world ("Atlantis", "Oceania", 500000)

Which SQL command removes all records from the 'world' table where the 'area' is less than 1000?

• REMOVE FROM world WHERE area < 1000

• DELETE FROM world WHERE area < 1000

• ERASE world WHERE area < 1000

• DROP RECORDS FROM world WHERE area < 1000

To change the 'gdp' of a country named "Albania" to 15000000000 in the 'world' table, which SQL command is correct?

• MODIFY world SET gdp = 15000000000 WHERE name = "Albania"

• UPDATE world SET gdp = 15000000000 WHERE name = "Albania"

• CHANGE world gdp = 15000000000 FOR name = "Albania"

• ALTER world SET gdp = 15000000000 WHERE name = "Albania"

What is the primary purpose of the JOIN clause in SQL when working with multiple tables?

• To permanently merge two tables into one.

• To delete duplicate records across tables.

• To combine data from two or more tables based on a common field.

• To create a new table from existing ones.

Which SQL command is used to completely remove an existing table and all its data from a database?

• DELETE TABLE

• REMOVE TABLE

• DROP TABLE

• ERASE TABLE

Which SQL clause is used to sort the results of a query in ascending or descending order?

• SORT

• GROUP BY

• ARRANGE BY

• ORDER BY