SQL Exercise: Display all information with specified conditions

Last update on February 10 2025 06:59:21 (UTC/GMT +8 hours)

From the following table, write a SQL query to locate the details of customers with grade values above 100. Return customer_id, cust_name, city, grade, and salesman_id.

Sample table: customer

 customer_id |   cust_name    |    city    | grade | salesman_id 
-------------+----------------+------------+-------+-------------
        3002 | Nick Rimando   | New York   |   100 |        5001
        3007 | Brad Davis     | New York   |   200 |        5001
        3005 | Graham Zusi    | California |   200 |        5002
        3008 | Julian Green   | London     |   300 |        5002
        3004 | Fabian Johnson | Paris      |   300 |        5006
        3009 | Geoff Cameron  | Berlin     |   100 |        5003
        3003 | Jozy Altidor   | Moscow     |   200 |        5007
        3001 | Brad Guzan     | London     |       |        5005

Sample Solution :

-- This query selects all columns from the 'customer' table.
SELECT *
-- Specifies the table from which to retrieve the data (in this case, 'customer').
FROM customer
-- Filters the rows to only include those where the 'grade' column has a value greater than 100.
WHERE grade > 100;

Output of the Query:

customer_id	cust_name	city		grade	salesman_id
3007		Brad Davis	New York	200		5001
3005		Graham Zusi	California	200		5002
3008		Julian Green	London		300		5002
3004		Fabian Johnson	Paris		300		5006
3003		Jozy Altidor	Moscow		200		5007

Code Explanation:

The said SQL query that is selecting all columns (*) from the 'customer' table where the value of the "grade" column is greater than 100. The query returns all rows from the 'customer' table whose "grade" column is greater than 100.

Relational Algebra Expression:

Relational Algebra Tree:

Explanation :

Visual presentation :

Practice Online

For more Practice: Solve these Related Problems:

• Write a SQL query to find customers whose grade is greater than 150 and return their customer ID, name, city, and grade.
• Write a SQL query to retrieve all customers with a grade value above 200, sorted by grade in descending order.
• Write a SQL query to display customers with a grade higher than 100 who belong to the city of 'London'.
• Write a SQL query to list customers whose grade exceeds 100 and are assigned to salesman_id 5001.

Have another way to solve this solution? Contribute your code (and comments) through Disqus.

Previous SQL Exercise: SQL Boolean and Relational Operators Exercises Home
Next SQL Exercise: Information using AND operator with given conditions.