I have parcel layer (geodatabase), which has total number of 250,000 parcels, and I want check if the parcel is duplicated.

In other words I want to find out the the rows which have the same Block number, Parcel Number in a certain Location.

I am wondering if there is a method to do that?

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    Are you working with ArcGIS for Desktop? Are you looking for a programmatic solution or an out-of-the-box solution (or either)?
    – Aaron
    Oct 17 '14 at 21:43
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    You can use the edit button beneath your question to improve it with details that potential answerers request via comments.
    – PolyGeo
    Oct 17 '14 at 21:47

Assuming ArcGIS, the Find Identical (Data Management) tool will identify duplicate values, you specify which field to test against.

Another way would be to right-click -> 'summarize' your Block Number/Parcel Number field, if they are all meant to singular entities, the duplicates will number greater than 1.

Joining your 2 fields into 1 should make this possible.

  • Thanks Maksim,is there any method to select them from the the table since my selection should be based on the 3 fields ( Block Number field ,Parcel Number field, and Location field). your method seems good when i have ( block # and parcel # ) in the same field . and the other thing that i need to correct the error in the summarize method seems to be hard to fix the duplicated numbers because of the large number of records Oct 17 '14 at 21:13
  • @Ahmadsaleh If you have any follow up questions they are best researched/asked separately. As someone new to our focussed Q&A format I recommend taking the Tour.
    – PolyGeo
    Oct 17 '14 at 21:46
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    With the summarize method you can do a summary to get the Min and Max of the ObjectID field. If there are only 2 duplicates then you would be able to use a relate form one or both of those fields to select and fix one of the two ObjectIDs. If 3 or more duplicates exist, but not more than 5 duplicates, then you would have to fix one of the ObjectIDs and then reprocess the summary 2 or three more times, each time fixing one of the incorrect ObjectIDs. Many more than 5 duplicates and you would need to concatenate values to make this work efficiently. Oct 18 '14 at 0:32
  • @RichardFairhurst Thanks for your time and help , please see the below screen shot which displays my problem in a better way , !SEE Screenshot,,,, I need the a way to know that objectid 3 and 4 are identical based on the 3 fields (Parcel #, Block#, Location) Oct 18 '14 at 16:35
  • The Summary Statistics tool in the Analysis toolbox, Statistics toolset lets you use the 3 fields as your case fields so that the unique combinations of the values in those 3 fields will be collapsed to a single row. Use the ObjectID twice in the summary field list to get the Min and Max summaries of those values. When it finishes, use the Select By Attribute to select all records with a Frequency greater than 1. You can create a relate to your original table using the original ObjectID related to either the Min_ObjectID or Max_ObjectID of the summary to select one of the duplicate records. Oct 18 '14 at 17:05

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