SQL Practice
SQL 75
All Questions
Skill Topics
Basics & Filtering Aggregation & Grouping Joins (All Types) Subqueries & Correlated CTEs & Adv. Subqueries Window Functions Advanced & Tricky Schema Design & Opt.
All Questions Question of the Day
75 / 95
Practice Mode
Log in

76. Correlated Subquery: Highest Cost

Hard Subqueries & CTEs
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

Click a table's header to toggle expand/collapse.
patients
10 cols
doctors
4 cols
admissions
7 cols
province_names
2 cols

Reference Solution

Expected SQL 
SELECT * FROM admissions a1 WHERE admission_cost = (SELECT MAX(admission_cost) FROM admissions a2 WHERE a2.patient_id = a1.patient_id);
SQL Editor
Ctrl+Enter to run
Console Output

Console Terminal

Write your query and click "Run Query" (Ctrl + Enter) to see results and testcase validation.

Ready