A student that completes this project shows that they can:

• Query data from a single table
• Query data from multiple tables
• Create a new datadaase using PostgreSQL

Working with SQL

Surf to SQL Try Editor at W3Schools.com
Answer the following data queries. Keep track of the SQL you write by pasting it into this document under its appropriate header below. You will be submitting that through the regular fork, change, pull process.

SELECT * FROM customers WHERE city = 'London'

SELECT * FROM customers WHERE postalcode = 1010

SELECT phone FROM suppliers WHERE SupplierID = 11

SELECT orderdate FROM orders ORDER BY orderdate DESC

TSELECT * FROM suppliers WHERE length(suppliername)>20

SELECT * FROM customers WHERE customername like'%market%'

Don't forget the wildcard '%' symbols at the beginning and end of your substring to denote it can appear anywhere in the string in question

INSERT INTO CUSTOMERS (customername, contactname, address, postalcode, country) VALUES ('The Shire', 'Bilbo Baggins', '1 Hobbit-Hole in Bag end','111', 'Middle Earth')

UPDATE customers SET postalcode = 11122 WHERE contactname = 'Bilbo Baggins'

SELECT customername, COUNT(orderid) AS OrdersPerCustomer FROM orders o JOIN customers c ON o.customerid = c.customerid GROUP BY c.ContactName

There is more information about the COUNT clause on W3 Schools

SELECT customername, COUNT(orderid) AS OrdersPerCustomer FROM orders o JOIN customers c ON o.customerid = c.customerid GROUP BY c.ContactName ORDER BY OrdersPerCustomer DESC

SELECT c.city, COUNT(orderid) AS OrdersPerCity FROM orders o JOIN customers c ON o.customerid = c.customerid GROUP BY c.city ORDER BY OrdersPerCity DESC

This is done with a DELETE query

In the WHERE clause, you can provide another list with an IN keyword this list can be the result of another SELECT query. Write a query to return a list of CustomerIDs that meet the criteria above. Pass that to the IN keyword of the WHERE clause as the list of IDs to be deleted

Use a LEFT JOIN to join the Orders table onto the Customers table and check for a NULL value in the OrderID column

• use pgAdmin to create a database, naming it budget.

• add an accounts table with the following schema:

  • id, numeric value with no decimal places that should autoincrement.
  • name, string, add whatever is necessary to make searching by name faster.
  • budget numeric value.

• constraints

  • the id should be the primary key for the table.
  • account name should be unique.
  • account budget is required.