SQL Practice
SQL 75
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Skill Topics
Basics & Filtering Aggregation & Grouping Joins (All Types) Subqueries & Correlated CTEs & Adv. Subqueries Window Functions Advanced & Tricky Schema Design & Opt.
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24 / 75
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24. Unmatched Patients Analysis

Medium Microsoft Joins (All Types)
Query Rules
  • The query columns and order must match the expected result schema.
  • NULL values should be handled appropriately where applicable.
  • The grader compares output values and sorting order to evaluate.

Schema Browser

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patients
10 cols
doctors
4 cols
admissions
7 cols
province_names
2 cols

Reference Solution

Expected SQL 
SELECT p.patient_id, p.first_name, p.last_name FROM patients p LEFT JOIN admissions a ON p.patient_id = a.patient_id WHERE a.admission_id IS NULL;
SQL Editor
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Console Output

Console Terminal

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