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SQL SORTING and FILTERING on HR Database: Display all the information for all employees without any department number

SQL SORTING and FILTERING on HR Database: Exercise-4 with Solution

4. From the following table, write a SQL query to find those employees who have no department number. Return employee_id, first_name, last_name, email,phone_number,hire_date, job_id, salary,commission_pct,manager_id and department_id.

Sample table: employees


Sample Solution:

SELECT *
 FROM employees
  WHERE department_id IS NULL;

Sample Output:

employee_id | first_name | last_name | email | phone_number | hire_date | job_id | salary | commission_pct | manager_id | department_id
-------------+------------+-----------+-------+--------------+-----------+--------+--------+----------------+------------+-------------
(0 rows)

Relational Algebra Expression:

Relational Algebra Expression: Display all the information for all employees without any department number.

Relational Algebra Tree:

Relational Algebra Tree: Display all the information for all employees without any department number.

Practice Online


HR database model

Query Visualization:

Duration:

Query visualization of Display all the information for all employees without any department number - Duration

Rows:

Query visualization of Display all the information for all employees without any department number - Rows

Cost:

Query visualization of Display all the information for all employees without any department number - Cost

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Previous: From the following table, write a SQL query to find those employees whose last name is "McEwen". Return first name, last name and department ID.
Next: From the following table, write a SQL query to find the details of 'Marketing' department. Return all fields.

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SQL: Tips of the Day

MySQL export schema without data

mysqldump -h yourhostnameorIP -u root -p --no-data dbname > schema.sql

Ref: https://bit.ly/3xzB9dS