SQL-FOR-DATA-ANALYSIS

PostgreSQL project for analyzing warehouse and retail sales with the following questions.

• what is the total retail sales for each supplier?

QUERY:

select supplier, sum(retailsales) as total_retail_sales
from project 
group by supplier;

RESULT:

• what is the total retail sales for each combination of supplier and month

QUERY:

select supplier, year, month, sum(retailsales) as total_retail_sales
from project 
group by supplier, year, month;

RESULT:

• what is the maximum warehouse sales for each item description?

QUERY:

select itemdescription, max(retailsales) as max_warehouse_sales
from project 
group by itemdescription;

RESULT:

• what is the average retail transfer for each year

QUERY:

select year, avg(retailtransfers) as avg_retail_transfers
from project 
group by year;

RESULT:

• for each item description, what is the difference between the maximum and minimum retail sales? QUERY:

select itemdescription, max(retailsales) - min(retailsales) as diff_max_min_retail_sales
from project 
group by itemdescription;

RESULT:

• what is the total retail sales for each supplier, broken down by year and month

QUERY:

select year, month, supplier,
       sum(retailsales) over (partition by supplier, year, month) as total_retail_sales
from project;

RESULT:

• what is the running total of retail sales for each item type, order by month? QUERY:

select year, month, itemtype,
       sum(retailsales) over (partition by itemtype order by month) as running_total_retail_sales
from project;

RESULT:

• what is the difference in retail sales between each month and the previous month, for each supplier and item type? QUERY:

select year, month, supplier, itemtype,
       retailsales - lag(retailsales) over (partition by supplier, itemtype order by year, month) as diff_retail_sales
from project; 

RESULT:

• what is the average retail sales for each item type compared to the overall average retail sales across all item types for each year?
• What is the percentage of retail sales for each supplier, compared to the total retail sales across all suppliers, broken down by year and month?
• What is the month with the highest retail transfer for each supplier, for the past 12 months?

NOTE: This is just a sample of the query and results