Repos-que-me-gustan/devops-exercises
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Added extra question, addressed some formatting issues

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zdj21jdz 2019-10-20 23:47:24 -04:00
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@ -3,7 +3,7 @@
:information_source:  This repository contains interview questions on various DevOps related topics
:bar_chart:  There are currently **300** questions
:bar_chart:  There are currently **312** questions
:warning:  You don't need to know how to answer all the questions in this repo. DevOps is not about knowing all :)
@ -2017,6 +2017,7 @@ A short way of using if/else. An example:
<summary>What does SQL stand for?</summary><br><b>
Structured Query Language
</b></details>
<details>
@ -2103,6 +2104,7 @@ Customer_ID | Customer_Name | Items_in_cart | Cash_spent_to_Date
100206 | Bobby Frank | 1 | 100.20
**ORDERS**
Customer_ID | Order_ID | Item | Price | Date_sold
------------ | ------------- | ------------- | ------------- | -------------
100206 | A123 | Rubber Ducky | 2.20 | 2019-09-18
@ -2117,38 +2119,30 @@ Customer_ID | Order_ID | Item | Price | Date_sold
<details>
<summary>How would I select all fields from this table?</summary><br><b>
Select *
Select * <br>
From Customers;
</b></details>
<details>
<summary>How many items are in John's cart?</summary><br><b>
Select Items_in_cart
From Customers
Select Items_in_cart <br>
From Customers <br>
Where Customer_Name = "John Smith";
</b></details>
<details>
<summary>What is the sum of all the cash spent across all customers?</summary><br><b>
Select SUM(Cash_spent_to_Date) as SUM_CASH
Select SUM(Cash_spent_to_Date) as SUM_CASH <br>
From Customers;
</b></details>
<details>
<summary>How many people have items in their cart?</summary><br><b>
Select count(1) as Number_of_People_w_items
From Customers
where Items_in_cart > 0;
</b></details>
<details>
<summary>How many people have items in their cart?</summary><br><b>
Select count(1) as Number_of_People_w_items
From Customers
Select count(1) as Number_of_People_w_items <br>
From Customers <br>
where Items_in_cart > 0;
</b></details>
@ -2159,9 +2153,42 @@ You would join them on the unique key. In this case, the unique key is Customer_
both the Customers table and Orders table
</b></details>
<details>
<summary>How would you show which customer ordered which items?</summary><br><b>
Select c.Customer_Name, o.Item <br>
From Customers c <br>
Left Join Orders o <br>
On c.Customer_ID = o.Customer_ID;
</b></details>
<a name="sql-advanced"></a>
#### Advanced
<details>
<summary>Using a with statement, how would you show who ordered cat food, and the total amount of money spent?</summary><br><b>
with cat_food as ( <br>
Select Customer_ID, SUM(Price) as TOTAL_PRICE <br>
From Orders <br>
Where Item like "%Cat Food%" <br>
Group by Customer_ID <br>
) <br>
Select Customer_name, TOTAL_PRICE <br>
From Customers c <br>
Inner JOIN cat_food f <br>
ON c.Customer_ID = f.Customer_ID <br>
where c.Customer_ID in (Select Customer_ID from cat_food);
Although this was a simple statement, the "with" clause really shines is when
a complex query needs to be run on a table before joining to another. With statements are nice,
because you create a pseudo temp when running your query, instead of creating a whole new table.
The Sum of all the purchases of cat food weren't readily available, so we used a with statement to create
the pseudo table to retrieve the sum of the prices spent by each customer, then join the table normally.
</b></details>
## Scenarios
Scenarios are questions which don't have verbal answer and require you one of the following: