Duplicate entry in text field

hello please i which to know the fonction i can use to prevent duplication in a text field once a data is entered such a way data entry is done once.

have created a pull data option and i which the id cannot be entered more than one time

thanks

@pavlov, could you provide more details on this?

yes kal_lam i have previously collected data in the field with kobo for househould and ID household was auto generated. now i wish to do a second collection in which this question may permit to auto generate data from the pevious collection according to different localities after you must have entered the ID code . i wish that once an ID code have been entered in a previous questionnaire the next should not permit the entery of the same ID so as to prevent duplicates. please have you understood this?

@pavlov, this is what I understood from your post. Correct me if I misunderstood you. So you have a survey project. You are collecting data in the field. You have already collected data for id 1, 2, 3, etc. Now you do not wish your team to collect the data for id 1, 2, and 3 that have already been submitted to the server. Did I get it correctly?