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Relational Database Experience
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Relational Database Experience

MediumSQL · PostgreSQL

Problem

How much hands-on experience do you have with relational databases (e.g. PostgreSQL, SQL Server)?

To demonstrate practical experience, write a query against the provided contractor and payment tables. Return contractors with at least two completed payments during 2025 and completed payments totaling at least 1,000.

Output

  1. One row per qualifying contractor with contractor_id, contractor_name, country, completed_payment_count, total_completed_amount, and latest_payment_date.
  2. Order by total_completed_amount descending, then contractor_name ascending.

Schema

contractors
ColumnTypeDescription
contractor_idPKINTUnique contractor identifier
contractor_nameVARCHAR(100)Contractor display name
countryVARCHAR(80)Contractor country
start_dateDATEContract start date
statusVARCHAR(30)Current contractor status
payments
ColumnTypeDescription
payment_idPKINTUnique payment identifier
contractor_idINTContractor receiving the payment
payment_dateDATEDate of payment
amountNUMERIC(12,2)Payment amount
payment_statusVARCHAR(30)Payment processing status
Tablescontractorspayments
Interviewer

Your question is Relational Database Experience. Start with the requirements and the two tables in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

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CodePostgreSQL
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Run your query to see results here.