sql-select

Question 1

What is SQL and how is it different from languages like JavaScript?

Answer 1

It is a declarative programming language which means you ask the language to do something and it finds a way to return a result while JS is an imperative language which means you tell the language what to do and how to do it.

Question 2

How do you retrieve specific columns from a database table?

Answer 2

Use the SELECT keyword followed by names of columns in double quotes, separated by commas. Then use the FROM keyword followed by the table name.

Question 3

How do you filter rows based on some specific criteria?

Answer 3

The WHERE keyword filters the amount of rows based on a comparison of a column value to a filter value that you decide

Question 4

What are the benefits of formatting your SQL?

Answer 4

Formatting provides a consistent style which increases readability.

Question 5

What are four comparison operators that can be used in a where clause?

Answer 5

”=”, “<”, “>”, “!=”

Question 6

How do you limit the number of rows returned in a result set?

Answer 6

Use the LIMIT keyword followed by an integer representing the amount of rows to return

Question 7

How do you retrieve all columns from a database table?

Answer 7

Use the SELECT keyword followed by the * followed by the keyword FROM followed by the table name

Question 8

How do you control the sort order of a result set?

Answer 8

Use the keyword ORDER BY followed by a column name followed by keyword DESC if you want the data to be in descending order instead of ascending order.