Location : Noida (UP) India
Education : Graduate or above in computer science / engineering from a recognized institute
Business applications are often modeled as transactional systems, where each transaction performs a specific action (usually update) upon a database with a defined schema.
Further, most transactions have a form type user interface, where the user fills in desired data and hits a button to send the data to the server. Validations may be performed upon the data submitted by the user before sending it to the server.
Given below is a simple example schema for an inventory database:
create table products (
id integer,
name text,
PRIMARY KEY(id)
);
create table customers (
id integer,
name text,
address1 text,
address2 text,
email_id text,
phone text,
PRIMARY KEY(id)
);
create table suppliers (
id integer,
name text,
address1 text,
address2 text,
email_id text,
phone text,
PRIMARY KEY(id)
);
create table sales (
id integer,
customer_id integer,
date date,
PRIMARY KEY(id),
CONSTRAINT fkey_customer
FOREIGN KEY(customer_id)
REFERENCES customers(id)
);
create table sales_items(
sales_id integer,
product_id integer,
qty integer,
sale_price integer,
CONSTRAINT fkey_sales
FOREIGN KEY(sales_id)
REFERENCES sales(id),
CONSTRAINT fkey_products
FOREIGN KEY(product_id)
REFERENCES products(id)
);
create table purchases (
id integer,
vendor_id integer,
date date,
PRIMARY KEY(id),
CONSTRAINT fkey_vendor
FOREIGN KEY(vendor_id)
REFERENCES suppliers(id)
);
create table purchase_items (
purchase_id integer,
product_id integer,
qty integer,
purchase_price integer,
CONSTRAINT fkey_purchase
FOREIGN KEY(purchase_id)
REFERENCES purchases(id),
CONSTRAINT fkey_products
FOREIGN KEY(product_id)
REFERENCES products(id)
);
insert into products values (101, 'product1');
insert into products values (102, 'product2');
insert into products values (103, 'product3');
insert into products values (104, 'product4');
insert into customers values (201, 'customer1', 'noida', 'delhi', 'customer1@xyz.com', '0123456');
insert into customers values (202, 'customer2', 'faridabad', 'gurugram', 'customer2@xyz.com', '0159753');
insert into customers values (203, 'customer3', 'gurugram', 'delhi', 'customer3@xyz.com', '0147852');
insert into suppliers values (301, 'supplier1', 'ghaziabad', 'noida', 'supplier1@xyz.com', '0128452');
insert into suppliers values (302, 'supplier2', 'sonipat', 'gurugram', 'supplier2@xyz.com', '0179793');
insert into suppliers values (303, 'supplier3', 'surat', 'nagpur', 'supplier3@xyz.com', '0117855');
This simple database keeps a record of all sales and purchases by customer and vendor, updating the relevant tables as transactions are done.
NOTE - The schema dump provided is compatible with PostgreSQL database, You can change schema according to database type.
Question 1
Write stored procedures in SQL to implement the purchase and sale transactions.
The purchase transaction inputs are : vendor_id, date, product_id, qty, purchase_price ...]
// more than one product can be purchased at a time from a vendor
The purchase transaction creates a record of the purchase in appropriate tables.
The sale transaction inputs are : customer_id, date, product_id, qty, sale_price ...]
// more than one product can be sold at a time to a customer.
The sale transaction creates a record of the sale in appropriate tables.
You can assume a given set of products, customers, and vendors and make sample data on your own to test the transactions.
Submit a snapshot of your database with sample data, and the results of executing sale and purchase transactions.
Question 2
Write a stored procedure to generate a stock report for a date range.
select stock_report (date1 date, date2 date);
This report shows the following columns
product_id product_name opening_balance qty_in qty_out qty_net closing_balance_date2
The report calculates opening balances from "beginning of time" to date1, then computes qty_in and qty_out using purchases and sales respectively, then calculates qty_net by qty_in and qty_out between date1 and date2 and finally computes the closing balance on date2.
You may need to write multiple sql statements inside the body of the stock_report stored procedure.
You can use any language for database programming, including PLV8 (embeddeded javascript), PL/SQL or any other embedded language embedded in a SQL server.
Bonus : Can you make the report more efficient ?
To submit your work send your running code in text file and mail to careers@saralweb.com with subject "SDE Assignment - Nov 2022" .
Candidates will be considered in the order of assignment submission. Please submit your assignment as soon as possible.