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SQL exercises

SQL UNION Exercises: Create a union of two queries that shows the names, cities, and ratings of all customers with a comment string

SQL UNION : Exercise-8 with Solution

8. Write a query to create a union of two queries that shows the names, cities, and ratings of all customers. Those with a rating of 300 or greater will also have the words High Rating, while the others will have the words Low Rating.

Sample table: Customer


Sample Solution:

SELECT customer_id, city, grade, 'High Rating'
FROM customer
WHERE grade >= 300
UNION
(SELECT customer_id, city, grade, 'Low Rating'
FROM customer
WHERE grade < 300)

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
3005		California	200		Low Rating
3007		New York	200		Low Rating
3009		Berlin		100		Low Rating

Practice Online


Inventory database model

Query Visualization:

Duration:

Query visualization of Create a union of two queries that shows the names, cities, and ratings of all customers with a comment string - Duration

Rows:

Query visualization of Create a union of two queries that shows the names, cities, and ratings of all customers with a comment string - Rows

Cost:

Query visualization of Create a union of two queries that shows the names, cities, and ratings of all customers with a comment string - Cost

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Previous: Write a query to that appends strings to the selected fields, indicating whether or not a specified salesman was matched to a customer in his city.
Next: Write a query that produces the name and number of each salesman and each customer with more than one current order. Put the results in alphabetical order.

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