Premise
– Contains any needed background information
Request
– The actual question, what you are to solve
Notes
– A space if you feel like including notes of any kind for the given question
Premise:

You have a table named “TRADES” with the following six columns:

Column Name Data Type Description
Date DATE The calendar date on which the trade took place.
Firm VARCHAR(255) A symbol representing the Broker/Dealer who conducted the trade.
Symbol VARCHAR(10) The security traded.
Side VARCHAR(1) Denotes whether the trade was a buy (purchase) or a sell (sale) of a security.
Quantity BIGINT The number of shares involved in the trade.
Price DECIMAL(18,8) The dollar price per share traded.
You write a query looking for all trades in the month of August 2019. The query returns the following:

DATE FIRM SYMBOL SIDE QUANTITY PRICE
8/5/2019 ABC 123 B 200 41
8/5/2019 CDE 456 B 601 60
8/5/2019 ABC 789 S 600 70
8/5/2019 CDE 789 S 600 70
8/5/2019 FGH 456 B 200 62
8/6/2019 3CDE 456 X 300 61
8/8/2019 ABC 123 B 300 40
8/9/2019 ABC 123 S 300 30
8/9/2019 FGH 789 B 2100 71
8/10/2019 CDE 456 S 1100 63
Questions:

1）Conduct an analysis of the data set returned by your query. Write a paragraph describing your analysis.  Please also note any questions or assumptions made about this data.

2）Your business user asks you to show them a table output that includes an additional column categorizing the TRADES data into volume based Tiers, with a column named ‘Tier’. Quantities between 0-250 will be considered ‘Small’, quantities greater than ‘Small’ but less than or equal to 500 will be considered ‘Medium’, quantities greater than ‘Medium’ but less than or equal to 500 will be considered ‘Large’, and quantities greater than ‘Tier 3’ will be considered ‘Very Large’ .

a. Please write the SQL query you would use to add the column to the table output.

b. Please show the exact results you expect based on your SQL query.

3)Your business user asks you to show them a table output summarizing the TRADES data (Buy and Sell) on week-by-week basis.

a. Please write the SQL query you would use to query this table.

b. Please show the exact results you expect based on your SQL query.

Notes:
You need to describe in writing how to accomplish a task.  Your audience has never completed this task before.

Question:

In a few paragraphs, please describe how to complete a task of your choice.  You may choose a task of your own liking or one of the sample tasks below:

1)How to make a peanut butter and jelly sandwich

2)How to get leaves off a lawn

3)How to make a cup of tea

Notes:
Below is a snapshot of data from two tables: “Orders” and “Customers”. You find the following documentation:

The ORDERS table gets updated at the end of every day
The CUSTOMERS table gets updated at the end of every week SQL project案例
ORDERS Table
Field Name Description
ORDER_DT Date the order was placed.
ORDER_ID A unique identifier for each order.
ORDER_STATUS The status of an order.
CUSTOMER_ID Identifies a unique customer.
CUSTOMERS table
Field Name Description
CUSTOMER_ID The unique identifier of the Customer trading in the market
CUSTOMER_STATUS The Customer’s account status. It should be ‘Active’ in order to be eligible for Order processing.
CUSTOMER_FNAME First name of a customer.
CUSTOMER_MNAME Middle name of a customer.
CUSTOMER_LNAME Last name of a customer.
GENDER Gender of a customer.
AGE Age of a customer.

Table Name: ORDERS
ORDER_DT ORDER_ID ORDER_STATUS ORDER_STATUS_CD CUSTOMER_ID
2/1/2016 1000002 Completed S 4
2/2/2016 2000008 Processing P 6
2/2/2016 2000009 Completed S 7
2/2/2016 2000010 Completed S 7
2/3/2016 3000008 Processing P 6
2/3/2016 3000009 Cancelled C 6
2/3/2016 3000010 Cancelled C 4
2/3/2016 3000011 On Hold H 3
2/3/2016 3000012 Processing P 7
2/4/2016 4000005 Completed S 6
(Continued on next page)

Table Name: CUSTOMERS
CUSTOMER_ID STATUS FNAME MNAME LNAME GENDER AGE
1 Active John Smith M 70
2 Active James Emitt Madison M 68
3 Active Joe Anthony Diggs M 55
4 Inactive Adam Lambert M 40
5 Active Marcus Dallas M 81
6 Active Steve Eugene Bullock M 62
7 Active Naomi Patel F 33
8 Active Alexander Pope M 29
9 Inactive Peter Chandler M 36
Any coding language can be used to query the data.

Question:
1)Your business user asks you to combine the details from these two tables in one table output, without any duplicated columns.

A. Please write the query you would use to query this (note which language you are using).

B. Please show the exact results you expect based on your SQL query.

C. If you make assumptions to complete the task, please document them.

2)Through an investigation, your business user has learnt that there has been an order that was processed successfully by mistake.

A. Please write the query you would use to validate (or disprove) this finding (note which language you are using).

B. Please show the exact results you expect based on your SQL query.

C. If you make assumptions to complete the task, please document them.

Notes:
The following are stand-alone SQL questions.  If you are unable to answer a question, please document your approach and proposed next steps.  For each of the below, please show the exact results that you expect based on your SQL query.

Question:
1) Is this a valid SQL statement?

SELECT CUSTOMERS.GENDER, count(DISTINCT CUSTOMERS.CUSTOMER_ID), count(*), sum(DISTINCT CUSTOMERS.CUSTOMER_ID)

FROM CUSTOMERS

GROUP BY CUSTOMERS.GENDER;

2) Is this a valid SQL statement?

SELECT CUSTOMERS.GENDER, count(DISTINCT CUSTOMERS. CUSTOMER_ID), count(*), count(DISTINCT CUSTOMERS.AGE)

FROM CUSTOMERS

GROUP BY CUSTOMERS.GENDER;