sql-select

Question 1

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

Answer 1

• Structured Query Language (SQL) is the primary way of interacting with relational databases. It is a powerful way of retrieving, creating, and manipulating data in a relational database.
• SQL is a declarative programming language, meaning you describe the results you want and the programming environment comes up with its plan for getting those result.
• while JavaScript is an imperative programming language, meaning that you have to tell JavaScript what to do and how to do it.

Question 2

How do you retrieve specific columns from a database table?

Answer 2

select keyword and followed by column name surrounded by double quotes

Question 3

How do you filter rows based on some specific criteria?

Answer 3

where clause and followed by column name surrounded by double quotes , equal sign, and values wrapped in single quotes.

Question 4

What are the benefits of formatting your SQL?

Answer 4

for consistent style and better 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

limit clause followed by an integer number

Question 7

How do you retrieve all columns from a database table?

Answer 7

select * (asterisk)

Question 8

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

Answer 8

order by clause, followed by a column name in double quotes, the default sort order is ascending order, or you can add desc keyword to switch to descending order.