SQL Exercise: Display the unique designations for the employees

Last update on April 18 2023 06:45:13 (UTC/GMT +8 hours)

SQL employee Database: Exercise-3 with Solution

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3. From the following table, write a SQL query to find the unique designations of the employees. Return job name.

Sample table: employees

Pictorial Presentation:

SQL exercises on employee Database: Display the unique designations for the employees

Sample Solution:

SELECT DISTINCT job_name 
FROM employees;

Sample Output:

 job_name
-----------
 CLERK
 SALESMAN
 MANAGER
 PRESIDENT
 ANALYST
(5 rows)

Explanation:

The said query in SQL that retrieves all distinct (unique) values in the "job_name" column of the 'employees' table .

The DISTINCT keyword eliminates duplicate values from the result set, so this query will only return a list of unique job names that are stored in the 'employees' table.

Relational Algebra Expression:

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Practice Online

Sample Database: employee

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Previous SQL Exercise: Find the salaries of all employees.
Next SQL Exercise: Employee names and salaries are increased by 15% in $.

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SQL: Tips of the Day

Concatenate strings of a string field in a PostgreSQL 'group by' query:

Input:

ID   COMPANY_ID   EMPLOYEE
1    1            Anna
2    1            Bill
3    2            Carol
4    2            Dave

SELECT company_id, string_agg(employee, ', ')
FROM mytable
GROUP BY company_id;

Output:

COMPANY_ID   EMPLOYEE
1            Anna, Bill
2            Carol, Dave

Database: PostgreSQL

Ref: https://bit.ly/2XTiRjq

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