interviewAdvanced SQL 12m est

Table Registration Deduplication

Problem Statement

Simulate identifying duplicate rows in a table. In our sandbox, write a query that returns the `id` of all duplicate records in the `customers` table, assuming that a duplicate is defined by having the same `name` and `email` as a prior registration (keep the record with the lowest `id`). Sort the output `id` ascending.

Skills Evaluated

DeduplicationROW_NUMBER OVERCTE
Write your SQL query in the editor on the right and click **Run Query**. The system runs your query and compares the result dataset with the official solution. Results must match row-for-row, column-for-column.

Expected Output Format

Executing expected result set...
SQL Query WorkspaceSQLite v3.45 (WASM Mode)
QUICK INSERT:
1