Can I set unique identifier for a certain field to prevent same record be submitted

To prevent duplication of data by setting unique identifier on certain field (matching) in stored database of previous submissions to prevent duplicated records. Google Forms can do it. Can Jotform do this? How?

Yes, this is possible with a 'Unique Question' option in JotForm. Please follow the next guide.

How to set Form Limits Based on a Unique Question

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