Preventing Duplicate Rows in Dataverse Tables

PL-200 By islever Editorial Last updated

Short answer

B A duplicate detection rule only warns users; it does not prevent saving, so it fails to guarantee no duplicates exist.

Question

Note: This question is part of a series of questions that present the same scenario. Each question in the series contains a unique solution that might meet the stated goals. Some question sets might have more than one correct solution, while others might not have a correct solution. After you answer a question in this section, you will NOT be able to return to it. As a result, these questions will not appear in the review screen. A company uses a Dataverse environment. The environment is accessed from canvas and model-driven apps. The Dataverse environment contains a table that has the following columns: • Name • Company • Contacted On The company requires that the table not contain any duplicate rows when users create data in the environment. You need to implement a solution that meets the requirement. Solution: Create a duplicate detection rule for the columns. Does the solution meet the goal?
  1. Yes
  2. No Correct Answer

Key Takeaways

The exam tests the distinction between a warning mechanism (Duplicate Detection) and an enforcement mechanism (Alternate Keys). The trap is assuming that 'detecting' duplicates automatically stops the user from saving the record.

This question tests the capability of Microsoft Dataverse duplicate detection rules versus alternate keys for enforcing data integrity. The solution fails because detection rules only warn users, whereas the requirement demands preventing duplicate creation.

Common mistake: Candidates often choose 'Yes' because they believe Duplicate Detection Rules block saves, but these rules merely display a warning dialog allowing the user to proceed or cancel.

Expert Analysis

Why the Answer Is Correct

The correct answer is B (No). The requirement is to ensure the table does not contain any duplicate rows when users create data. A Duplicate Detection Rule in Dataverse identifies potential duplicates and presents a warning to the user, but it does not prevent the record from being saved. The user can override the warning and save the duplicate record anyway. Therefore, this solution does not meet the strict requirement of preventing duplicates.

Why the Other Options Are Wrong

Option A (Yes) is incorrect because it assumes the rule acts as a hard constraint. In reality, "Duplicate Detection" is a soft check. To strictly enforce uniqueness, you must use Alternate Keys, which are system-enforced unique constraints that throw an error if a duplicate is attempted. Since the proposed solution lacks this enforcement, it is insufficient.

Community Comment Notes

Community consensus strongly supports option B. As one commenter noted, "Only Alternate Keys can do that," highlighting the enforcement gap. Another user pointed out that duplicate detection rules may not even function correctly in Canvas apps, stating it "Doesn't work in canvas apps only in model driven." This reinforces that the solution is flawed both in its lack of enforcement and its limited scope across app types.

Exam Strategy

When a requirement states 'prevent', 'block', or 'ensure no duplicates', look for Alternate Keys or Unique Constraints. If the option suggests 'Duplicate Detection', remember it is a warning feature, not a blocking feature, unless specifically configured with other plugins.

Frequently Asked Questions

Why doesn't Duplicate Detection stop duplicates?

It displays a warning dialog but allows the user to click 'Save Anyway'. It is a advisory tool, not an enforcement constraint.

How to strictly prevent duplicates in Dataverse?

Use Alternate Keys. They act as unique constraints and will throw a runtime error if a duplicate value is submitted, blocking the save.

More PL-200 FAQ →

Community Votes

B
80%
A
20%

80% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 7 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 7

  1. webcreator 👍 6 Answered B
    A duplicate detection rule can check multiple columns within a table to see if duplicates exist. But it won't stop user from creating the record. Only Alternate Keys can do that.
  2. DaanEp 👍 4 Answered B
    Duplicate detection rules in Dataverse do not directly support creating rules based on multiple columns that form the key to a table. Duplicate detection rules typically allow you to define criteria for identifying duplicate records based on individual columns. So it can work in combination with an alternate key but not on it's own.
  3. jmccolly 👍 3 Answered A
    I think it's A (Yes). A duplicate detection rule can check multiple columns within a table to see if duplicates exist. Base Record Type: Table A Matching Record Type: Table A Then, define the fields you want to check for duplicates with an AND operator.
  4. 61be873 👍 3
    No Doesn't work in canvas apps only in model driven https://powerusers.microsoft.com/t5/Microsoft-Dataverse/Powerapps-canvas-app-does-not-respect-duplicate-detection-rules/td-p/2053503
  5. JohnChung 👍 2 Answered B
    The answer for this question should be No. Though duplicate detection rule triggers before you save data to existing records, it needs 2 tables to make a duplicate detection rule, "Base record and Matching record". Base record is the table for checking whether the subject of the new record exist or not. Matching record is the table the new record is going to be added to. This question mentions only one table, so the answer must be "No". https://learn.microsoft.com/en-us/power-platform/admin/set-up-duplicate-detection-rules-keep-data-clean
Show 2 more comments
  1. Smith_S 👍 2
    The Duplicate detection rule won't work to restrict duplicate records it always creates a record whereas an alternate will give a business error if a duplicate exist
  2. MrEz 👍 1
    A) Duplicate Detection Rule triggers before you save it. and suggests the existing records. You then can decide if it is a duplicate and you don't continue to save it. or maybe you decide it is NOT a duplicate because Name George Bush, both of them - senior and junior, happen to work for the same company, eg. Carlyle group, have e.g. a call on the same Date (we don't know if it is date only or date and time field, sheduled times could happen at same time, timestamp not but then it is almost never same) and maybe same time?! from this perspective it is even better as the alternate key

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