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Project Overview with SQL and PySpark
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Project Overview with SQL and PySpark

MediumSQL · PostgreSQL

Problem

Overall Project overview, Basic SQL (window function, max salary and joins) and pyspark (joins, read and write into delta and other format).

For the SQL portion, write a PostgreSQL query using the provided employee, department, project, and assignment data. Return employees whose salary equals the maximum salary in their department, including employees with no assigned projects.

Output

  1. One row per qualifying employee with department_name, employee_name, salary, department_max_salary, salary_rank, and project_count.
  2. Order by department name, then employee name.

Schema

employees
ColumnTypeDescription
employee_idPKINTUnique employee identifier
employee_nameVARCHAR(100)Employee name
department_idINTEmployee department identifier
salaryNUMERIC(12,2)Annual salary
departments
ColumnTypeDescription
department_idPKINTUnique department identifier
department_nameVARCHAR(100)Department name
projects
ColumnTypeDescription
project_idPKINTUnique project identifier
project_nameVARCHAR(150)Project name
employee_projects
ColumnTypeDescription
employee_idINTAssigned employee identifier
project_idINTAssigned project identifier
Tablesemployeesdepartmentsprojectsemployee_projects
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