Select features with same value in a given column

Question

I first tried writing this post in generalities but realized it was more confusing that just giving the long version, so here goes.

I have a tree inventory that has property quads (in front of a house, to the left, etc) and then a sequence number so that each tree can be identified by its relative location on that property. Also I have street addresses and names among other attributes. My plan is to automate a way to update the sequence numbers.

My current plan to is concatenate a field for each unique location ("Address" + "StreetName" + "Quad".) I will also create another field with those but also the "Sequence_Num" added onto it.

My plan then is to Sort but the second unique field and then create a for loop that selects all trees by the first unique field and then generates an autoIncrement() value.

The problem is that right now I might have several trees with the same exact value for the second unique field (same "Sequence_Num") and I can't be sure it will sort correctly. So I want to find all trees that have the same Unique value for the 4 field concatentation (address, streetname, quad, sequence.)

Short recap, is there any way to find all features that have the same value for a given field?

For ArcGIS.

• mgri: Which GIS software you want to use?
• nsm91: @Midavalo ♦ How can I make this more specific? I feel like what I am asking for is very specific: finding only values in a field with a count > 1
• Midavalo: @nsm91 The new user tour states there should be only one question per question, however in asking for a solution for ArcGIS or QGIS you are essentially asking two questions. Please edit your question to focus on one GIS software package. If you need an answer for both, please ask the two questions separately.
• nsm91: @Midavalo ♦ I believe I discovered that you can create a summary table and then join it one-to-many to the original feature class, thus allowing you to just select by count > 1, can I edit then answer my own question?
• Midavalo: @nsm91 I'll reopen your question

Answer 1

I found that you can create a summary table of a given field, generating a count field, then use a one-to-many join. Then you would only have to query the count field for> 1.

• Jio: if you want to find features with identical field value you can use 'Find Identical' tool in ArcGIS.

Answer 2

If you 'Select Layer By Attribute', you can set up an SQL expression to find all the features that have the same value for a given field. For 'Selection Type' you should probably use ' New Selection', so that way a new column is created based off of the expression that you created.