SQL Practice
SQL 75
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Basics & Filtering Aggregation & Grouping Joins (All Types) Subqueries & Correlated CTEs & Adv. Subqueries Window Functions Advanced & Tricky Schema Design & Opt.
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330. Self JOIN for Duplicates

Hard TCS Joins
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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locations
3 cols
departments
3 cols
employees
6 cols
orders
6 cols

Reference Solution

Expected SQL 
SELECT DISTINCT e1.name FROM employees e1 JOIN employees e2 ON e1.name = e2.name AND e1.id != e2.id;
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Console Output

Console Terminal

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