Added extra question, addressed some formatting issues
This commit is contained in:
parent
5129a3a8a1
commit
ca469128df
57
README.md
57
README.md
@ -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:
|
||||
|
Loading…
Reference in New Issue
Block a user