SQL and Programming Concepts Worksheet

What is a condition in an if statement?

• A block of code that is always executed

• A variable assignment

• A function definition

• An expression that evaluates to either True or False

What does NULL represent in SQL?

• A default value

• Zero

• An empty string

• The absence of a value or an unknown value

What is the purpose of the WHERE clause in an SQL query?

• To specify the columns to retrieve

• To sort the data

• To filter data based on specific conditions

• To join tables

What does the SELECT clause specify in an SQL query?

• The fields or expressions to retrieve

• The database to connect to

• The tables from which data is retrieved

• The conditions for data filtering

What is the main reason for creating relationships between tables in a relational database?

• To reduce the number of rows

• To organize data efficiently and reduce redundancy

• To eliminate the need for primary keys

• To avoid NULL values

What does the DISTINCT keyword do in an SQL query?

• Sorts the results in ascending order

• Limits the fields returned

• Retrieves only unique values from a specified field or fields

• Deletes duplicate rows

What is SQL primarily used for?

• Managing and manipulating data in relational databases

• Designing web pages

• Developing mobile applications

• Creating graphics

Which of the following is the correct syntax for a basic SELECT statement in SQL?

• SELECT FROM table columns

• SELECT table.columns FROM database

• FROM table SELECT columns

• SELECT columns FROM database.table

What does the SUM function do in SQL?

• Sums the NULL values

• Sums the number of records

• Sums the non-NULL values in a column or expression

• Sums the number of distinct values

What is the result of a mathematical expression if any part of it is NULL?

• The result is the same as if NULL was not present

• NULL

• 0

• 1