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SQL Exercises: Highest grade for each of the cities of the customers

SQL Aggregate Functions: Exercise-8 with Solution

From the following table, write a SQL query to find the highest grade of the customers in each city. Return city, maximum grade.

Sample table: customer


Sample Solution:

SELECT city,MAX(grade) 
FROM customer 
GROUP BY city;

Output of the Query:

city		max
London		300
Paris		300
New York	200
California	200
Berlin		100
Moscow		200

Explanation Code

The said SQL statement retrieves the maximum "grade" value for each "city" in the 'customer' table. A "GROUP BY" clause is used in the query to group the 'customer' table according to a city, and a "MAX" function is used to determine the maximum grade for each group based on the "GROUP BY" clause.

Relational Algebra Expression:

Relational Algebra Expression: Find the highest grade for each of the cities of the customers.

Relational Algebra Tree:

Relational Algebra Tree: Find the highest grade for each of the cities of the customers.

Explanation:

Syntax of find the highest grade for each of the cities of the customers

Visual presentation :

Find the highest grade for each of the cities of the customers

Practice Online


Query Visualization:

Duration:

Query visualization of Find the highest grade for each of the cities of the customers - Duration

Rows:

Query visualization of Find the highest grade for each of the cities of the customers - Rows

Cost:

Query visualization of Find the highest grade for each of the cities of the customers - Cost

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Previous SQL Exercise: Find the minimum purchase amount of all the orders.
Next SQL Exercise: Highest purchase amount ordered by the each customer.

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SQL: Tips of the Day

What is the best way to paginate results in SQL Server?

SELECT  *
FROM    ( SELECT    ROW_NUMBER() OVER ( ORDER BY OrderDate ) AS RowNum, *
          FROM      Orders
          WHERE     OrderDate >= '1980-01-01'
        ) AS RowConstrainedResult
WHERE   RowNum >= 1
    AND RowNum < 20
ORDER BY RowNum

Database: SQL Server

Ref: https://bit.ly/3MGrNlk

 





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