SQL Exercises, Practice, Solution - UNION
SQL UNION [9 exercises with solution]
[An editor is available at the bottom of the page to write and execute the scripts. Go to the editor]
1. From the following tables, write a SQL query to find all salespeople and customers located in the city of London.
Sample table: Salesman
Sample table: Customer
Sample Output:
ID name ?column? 3001 Brad Guzan Customer 3008 Julian Green Customer 5005 Pit Alex Salesman
2. From the following tables, write a SQL query to find distinct salespeople and their cities. Return salesperson ID and city.
Sample table: Salesman
Sample table: Customer
Sample Output:
salesman_id city 5001 New York 5002 London 5002 California 5006 Paris .....
3. From the following tables, write a SQL query to find all those salespeople and customers who are involved in the inventory management system. Return salesperson ID, customer ID.
Sample table: orders
Sample table: customer
Sample Output:
salesman_id customer_id 5005 3001 5007 3003 5001 3007 5002 3008 .....
4. From the following table, write a SQL query to find the salespersons who generated the largest and smallest orders on each date. Return salesperson ID, name, order no., highest on/lowest on, order date.
Sample table: Salesman
Sample table: Orders
Sample Output:
salesman_id name ord_no ?column? ord_date 5001 James Hoog 70002 lowest on 2012-10-05 5001 James Hoog 70005 highest on 2012-07-27 5001 James Hoog 70005 lowest on 2012-07-27 5001 James Hoog 70008 highest on 2012-09-10 .....
5. From the following tables, write a SQL query to find the salespeople who generated the largest and smallest orders on each date. Sort the result-set on third field. Return salesperson ID, name, order no., highest on/lowest on, order date.
Sample table: Salesman
Sample table: Orders
Sample Output:
salesman_id name ord_no ?column? ord_date 5002 Nail Knite 70001 highest on 2012-10-05 5001 James Hoog 70002 lowest on 2012-10-05 5003 Lauson Hen 70003 highest on 2012-10-10 5003 Lauson Hen 70004 highest on 2012-08-17 .....
6. From the following tables, write a SQL query to find those salespeople who live in the same city where the customer lives as well as those who do not have customers in their cities by indicating 'NO MATCH'. Sort the result set on 2nd column (i.e. name) in descending order. Return salesperson ID, name, customer name, commission.
Sample table: Salesman
Sample table: Customer
Sample Output:
salesman_id name cust_name commission 5005 Pit Alex Julian Green 0.11 5005 Pit Alex Brad Guzan 0.11 5007 Paul Adam NO MATCH 0.13 5002 Nail Knite Fabian Johnson 0.13 .....
7. From the following tables, write a SQL query that appends strings to the selected fields, indicating whether the city of any salesperson is matched with the city of any customer. Return salesperson ID, name, city, MATCHED/NO MATCH.
Sample table: Salesman
Sample table: Customer
Sample Output:
salesman_id name city ?column? 5005 Pit Alex London MATCHED 5007 Paul Adam Rome NO MATCH 5002 Nail Knite Paris MATCHED 5006 Mc Lyon Paris MATCHED 5003 Lauson Hen San Jose NO MATCH 5001 James Hoog New York MATCHED
8. From the following table, write a SQL query to create a union of two queries that shows the customer id, cities, and ratings of all customers. Those with a rating of 300 or greater will have the words 'High Rating', while the others will have the words 'Low Rating'.
Sample table: Customer
Sample Output:
customer_id city grade ?column? 3002 New York 100 Low Rating 3003 Moscow 200 Low Rating 3004 Paris 300 High Rating 3008 London 300 High Rating ....
9. From the following table, write a SQL query to find those salespersons and customers who have placed more than one order. Return ID, name.
Sample table: Customer
Sample table: salesman
Sample table: orders
Sample Output:
ID NAME 3009 Geoff Cameron 3005 Graham Zusi 5001 James Hoog 5003 Lauson Hen 5002 Nail Knite 3002 Nick Rimando
More to Come !
Practice Online
Query visualizations are generated using Postgres Explain Visualizer (pev)
Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.