Replace Employee ID With The Unique Identifier
A easy-tier problem at 84% community acceptance, tagged with Database. Reported in interviews at Point72 and 2 others.
Point72, Infosys, and TCS all ask this one, and it looks deceptively simple. Replace Employee ID With The Unique Identifier is an EASY database problem with an 83.6% acceptance rate, which means most people who attempt it pass, but that also means you can't afford to miss it in a live assessment. The trick isn't algorithmic complexity, it's understanding how joins and aliases work in SQL when you need to map one identifier to another. If this hits your online assessment and you freeze on the join logic, StealthCoder solves it invisibly while you stay on camera.
Companies that ask "Replace Employee ID With The Unique Identifier"
Replace Employee ID With The Unique Identifier is the kind of problem that decides whether you pass. StealthCoder reads the problem on screen and surfaces a working solution in under 2 seconds. Invisible to screen share. The proctor sees nothing. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage.
Get StealthCoderThis problem forces you to replace one column's values with another using a join operation. The naive approach is a simple SELECT with an INNER JOIN, but candidates often miss edge cases: NULL handling, which table to join from, whether the ID being replaced is the primary key or a foreign key, and aliasing the result correctly. The acceptance rate sits high because the problem syntax is straightforward, but the SQL logic still trips people who haven't written joins in a while. The underlying pattern is a standard relational operation, but you need to read the schema carefully to know which columns reference which. During a live OA, if you blank on the exact join syntax or table structure, StealthCoder reads the problem and serves the working query immediately.
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Replace Employee ID With The Unique Identifier recycles across companies for a reason. It's easy-tier, and most candidates blank under the timer. StealthCoder is the hedge: an AI overlay invisible during screen share. It reads the problem and surfaces a working solution in under 2 seconds. Built by an engineer who got tired of watching his cohort grind for six months and still get filtered at the OA stage. Works on HackerRank, CodeSignal, CoderPad, and Karat.
Replace Employee ID With The Unique Identifier interview FAQ
Is this really asked at big companies like Point72?+
Yes. Point72, Infosys, and TCS all report asking it. 83.6% pass rate doesn't mean it's a gimme, it means candidates who study SQL joins answer it correctly. It's a screening filter for basic relational database competence.
What's the most common mistake on this problem?+
Getting the join condition backwards or joining on the wrong columns. Candidates often SELECT from the wrong table or forget to alias the replacement column, returning the old ID instead of the new one. Read the schema diagram before you write any SQL.
Is this more about SQL syntax or algorithm design?+
Pure SQL syntax and schema understanding. There's no algorithmic trick. The difficulty is EASY because joins are a fundamental relational operation. If you're comfortable with INNER JOIN, LEFT JOIN, and column aliasing, you'll pass it quickly.
Do I need to handle NULL values differently here?+
Depends on the schema provided in the problem. Most variants assume clean data, but always check whether the ID column or the replacement column can be NULL. The input will specify if you need COALESCE or an outer join.
How does this relate to the broader database topic?+
It's a foundational join pattern. Understanding how to replace values from one table with values from another is essential for real-world ETL and reporting. It's often a building block for more complex multi-table queries.
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