Introduction to SQL - Introducing Queries

Question 1

SQL is used to answer questions both within and across what?

Answer 1

relational databases tables

Question 2

You should analyze data in a spreadsheet if what two conditions are met?

Answer 2

1) data can fit in a spreadsheet
2) does not relate to other data

Question 3

What are keywords?

Answer 3

reserved words used to indicate what operations we want our code to perform

Question 4

What are the two most common keywords?

Answer 4

SELECT and FROM

Question 5

The SELECT keyword indicates what?

Answer 5

indicates which field should be selected from a table

Question 6

The FROM keyword indicates what?

Answer 6

indicates the table in which the selected fields are located

Question 7

What are 3 best practices with writing a query?

Answer 7

1) end query with a semicolon
2) capitalize keywords
2) keep tables/field names lowercase

Question 8

The results of a query is called what?

Answer 8

a result set

Question 9

True/False - Querying a databases with SQL changes the underlying database.

Answer 9

False - a query does not change the database itself or its tables rather it only changes the results

Question 10

True/False - We can save the SQL we write so that our collaborators can use it to query the database themselves.

Answer 10

True

Question 11

How can you change the order that fields are listed in the SQL output?

Answer 11

change the order of the field names after the SELECT keyword to change their order

Question 12

How can you select all the fields from a table without listing them out?

Answer 12

SELECT *

Question 13

What can we use to rename columns in SQL?

Answer 13

Aliasing

Question 14

What keyword do we use to alias a column?

Answer 14

AS

Question 15

What keyword do we use to get a list of records with only unique values?

Answer 15

SELECT DISTINCT

Question 16

If we use DISTINCT with multiple fields what gets returned?

Answer 16

only unique combinations of the fields will be returned but the fields themselves may still have duplicate values

Question 17

What is a view in SQL?

Answer 17

a saved SQL SELECT statement in the form of a virtual table

Question 18

The data a view contains is not generally stored in a database, rather it is the what that gets stored for future use?

Answer 18

query code

Question 19

What is a benefit of accessing views?

Answer 19

automatically updates when the data does

Question 20

True/False - There is no result set when creating a view.

Answer 20

True

Question 21

True/False - Once a view is created we can query it the same as a normal table by selecting from it.

Answer 21

True

Question 22

True/False - Once a view is created we can query it the same as a normal table by selecting from it.

Answer 22

True

Question 23

What are 5 characteristics of different SQL flavors?

Answer 23

1) both free and paid
2) all used with relational databases
3) majority of keywords are the same
4) all must follow universal standards
5) only the additions on top of these standards make flavors different

Question 24

What are the two most popular flavors of SQL?

Answer 24

1) PostgreSQL
2) SQL Server

Question 25

Where was PostgreSQL created? Who sponsored it?

Answer 25

University of California, Berkley that was sponsored by DARPA

Question 26

Who created SQL Server?

Answer 26

Microsoft

Question 27

What is Microsoft’s SQL flavor that is used with SQL server databases?

Answer 27

T-SQL

Question 28

Comparing PostgreSQL and SQL Server is like comparing what?

Answer 28

dialects of the same language (English/UK)