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SQL exercises on employee Database: List the manager no and the number of employees working for those managers in ascending order on manager id

SQL employee Database: Exercise-96 with Solution

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96. From the following table, write a SQL query to list the managers and number of employees work under them. Sort the result set in ascending order on manager. Return manager ID and number of employees under them.

Sample table: employees


Sample Solution:

SELECT w.manager_id,
       count(*)
FROM employees w,
     employees m
WHERE w.manager_id = m.emp_id
GROUP BY w.manager_id
ORDER BY w.manager_id ASC;

Sample Output:

  manager_id | count
------------+-------
      65646 |     2
      66928 |     5
      67832 |     1
      67858 |     1
      68319 |     3
      69062 |     1
(6 rows)

Relational Algebra Expression:

Relational Algebra Expression: List the manager no and the number of employees working for those managers in ascending order on manager id.

Relational Algebra Tree:

Relational Algebra Tree: List the manager no and the number of employees working for those managers in ascending order on manager id.

Practice Online


Sample Database: employee

employee database structure

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Previous: From the following table, write a SQL query to find those employees whose salary is in the range minimum and maximum salary (Begin and end values are included.). Return employee ID, name, salary and grade.
Next: From the following table, write a SQL query to count the number of employees of each designation in each department. Return department id, job name and number of employees.

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