Sql

General 1 question

#1
Comparisons vs. Functions
1. Improve the following query
```
SELECT COUNT(purchased_at)
FROM shawarma_purchases
WHERE purchased_at BETWEEN '2017-01-01' AND '2017-12-31';
```

SQL Self Assessment 11 questions

#2
What is SQL?
#3
How is SQL Different from NoSQL
#4
When is it best to use SQL? NoSQL?
#5
How would I select all fields from this table?
#6
How many items are in John's cart?
#7
What is the sum of all the cash spent across all customers?
#8
How many people have items in their cart?
#9
How would you join the customer table to the order table?
#10
How would you show which customer ordered which items?
#11
Using a with statement, how would you show who ordered cat food, and the total amount of money spent?

#12

Which of the following queries would you use?

SELECT count(*)                             SELECT count(*)
FROM shawarma_purchases                     FROM shawarma_purchases
WHERE                               vs.     WHERE
  YEAR(purchased_at) == '2017'              purchased_at >= '2017-01-01' AND
                                            purchased_at <= '2017-31-12'