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Deadlock and 3NF Basics
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Deadlock and 3NF Basics

MediumSQL · PostgreSQL

Problem

They asked basic questions like what is deadlock, 3NF and how deadlock occurs and Projects

For the project portion, write a PostgreSQL query that summarizes currently active project assignments while excluding cancelled projects. Include projects with no matching active employees.

Output

  1. One row per non-cancelled project with project_name, status, active_member_count, allocated_hours, and budget_band.
  2. Treat missing assignment totals as zero and classify budgets as High, Medium, or Low.
  3. Order by budget descending, then project name ascending.

Schema

projects
ColumnTypeDescription
project_idPKINTUnique project identifier
project_nameVARCHAR(150)Project name
statusVARCHAR(30)Current project status
budgetDECIMAL(12,2)Approved project budget
employees
ColumnTypeDescription
employee_idPKINTUnique employee identifier
employee_nameVARCHAR(120)Employee full name
roleVARCHAR(80)Employee project role
emailVARCHAR(160)Employee work email
project_assignments
ColumnTypeDescription
assignment_idPKINTUnique assignment identifier
project_idINTReferenced project
employee_idINTReferenced employee
hours_allocatedDECIMAL(8,2)Hours allocated to the assignment
ended_atDATEAssignment end date, NULL when active
Tablesprojectsemployeesproject_assignments
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