postgreSQL

Question 1

What is PostgreSQL and what are some alternative relational databases?

Answer 1

PostgreSQL is a relational database management system. Alternatives: MySQL, SQL Server, and Oracle

Question 2

What are some advantages of learning a relational database?

Answer 2

Having applications quickly retrieve or store complex data in an organized fashion. Data corruption is unlikely.

Question 3

What is one way to see if PostgreSQL is running?

Answer 3

sudo service postgresql status

Question 4

What is a database schema?

Answer 4

A collection of tables

Question 5

What is a table?

Answer 5

Collection of data items

Question 6

What is a row?

Answer 6

A data item

Question 7

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

Answer 7

It’s the primary way of interacting with relational databases. SQL is a declarative language which means the programmer describes the results they want and the programming environment gets them.

Question 8

How do you retrieve specific columns from a database table?

Answer 8

SELECT

Question 9

How do you filter rows based on some specific criteria?

Answer 9

where

Question 10

What are the benefits of formatting your SQL?

Answer 10

Consistent style and readability

Question 11

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

Answer 11

= != < >

Question 12

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

Answer 12

LIMIT

Question 13

How do you retrieve all columns from a database table?

Answer 13

*

Question 14

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

Answer 14

order by desc/asc

Question 15

How do you add a row to a SQL table?

Answer 15

INSERT

Question 16

What is a tuple?

Answer 16

(A list of values)

Question 17

How do you add multiple rows to a SQL table at once?

Answer 17

tuples separated by commas

Question 18

How do you get back the row being inserted into a table without a separate select statement?

Answer 18

returning *;

Question 19

How do you update rows in a database table?

Answer 19

UPDATE

Question 20

Why is it important to include a where clause in your update statements?

Answer 20

To select what to update/delete

Question 21

How do you delete rows from a database table?

Answer 21

DELETE

Question 22

How do you accidentally delete all rows from a table?

Answer 22

By not using where

Question 23

What is a foreign key?

Answer 23

Key that references another table

Question 24

How do you join two SQL tables?

Answer 24

join or inner join

Question 25

How do you temporarily rename columns or tables in a SQL statement?

Answer 25

something as somethingElse