topic Re: How do I copy attribute data to an existing shapefile? in New to GIS Questions

How do I copy attribute data to an existing shapefile?

DianneBoisvert — Wed, 02 Dec 2015 15:26:30 GMT

I have an existing table containing attribute data about crosswalks with no geometry. I also have a polyline layer for crosswalks that I want have the attribute data attached to. How do I get the data from the .dbf into the empty crosswalk feature class? Merge doesn't work b/c they're different data types. I can't do a join b/c there is no spatial reference yet. I figured once the data was in the shapefile I could use the "replace geometry" tool to draw in the lines depicting crosswalks but I'm not sure if that will work. Am I going about this all wrong?
Thanks,

Re: How do I copy attribute data to an existing shapefile?

Elizabeth_R_Jarvie — Wed, 02 Dec 2015 15:46:26 GMT

Is there an attribute in both layers that you can join on? Or do you have coordinates in your table to identify their location?

Re: How do I copy attribute data to an existing shapefile?

DanPatterson_Retired — Wed, 02 Dec 2015 15:48:56 GMT

You will have to provide an id field or some other key field in both tables, should they currently not exist, in order to join the tabular data to the file with the geometry. If you have geometry for both, you could do a spatial join...but you don't

Re: How do I copy attribute data to an existing shapefile?

DianneBoisvert — Wed, 02 Dec 2015 15:50:04 GMT

No, unfortunately the attribute table doesn't have any coordinates.

Re: How do I copy attribute data to an existing shapefile?

LukeSturtevant — Wed, 02 Dec 2015 16:41:03 GMT

What fields do you have in both tables? Could you maybe provide a screen shot of both tables to see if there is anything we can do to help?

Re: How do I copy attribute data to an existing shapefile?

ChadKopplin — Wed, 02 Dec 2015 16:54:52 GMT

Even if you have a name field identify each record you could join on this field, this could be bad if you have the same name for multiple records, but at least it should work for most of the records and cut down the amount of manual work that you may need to do.

Re: How do I copy attribute data to an existing shapefile?

Elizabeth_R_Jarvie — Wed, 02 Dec 2015 17:29:53 GMT

Do you have a streets layer that contains the same street names that are in your table? You could use that to identify the street your xwalks are on or even identify to two closest streets and create a join field.

You may find it just as fast to manually add the 'Intersection Number' (given that it is unique to the crosswalk) to your xwalks layer and join your table using the intersection number.

Re: How do I copy attribute data to an existing shapefile?

JoeBorgione — Wed, 02 Dec 2015 17:32:20 GMT

First off.... Don't use a shapefile. That's so 90's. Create an empty feature class in a File Geodatabase. Add a long integer field called JoinId.

I would then add a filed in your table (CopyCrosswlakblahblahbla) called JoinId. Type it as a long integer and then calc it to equal the OID. This ensures a unique record id but it will 'travel' with the data no matter where you store it in the futuer. The actual OID my change, but the JoinID remains static.

You have some work to do, but that's why there's payday. With the table open start creating you polygons and populate the JoinID in the polygon with the appropriate JoinID from your table.

When you are done, perform a join, or simply create a relationship class base on JoinID.

Re: How do I copy attribute data to an existing shapefile?

ChadKopplin — Wed, 02 Dec 2015 18:04:40 GMT

Dianne,

Keep in mind that the ObjectID is an internal ID and can change based on changes to the individual line segments themselves. Lets say you did not complete a line segment, so you create another segment to complete it, your shapefile will add a new ObjectID for that next segment. The shapefile also orders the ObjectID from TOP to Bottom and starts in the upper left and moves to the right. Just a few points to keep in mind as you create the line work.

Re: How do I copy attribute data to an existing shapefile?

DarrenWiens2 — Sun, 12 Dec 2021 06:56:40 GMT

You've already found the "right" way to do this (digitize the lines, keeping track of a unique ID to join back to the attributes), but here is a spectacularly wrong way to do it.

1.) Make a note of how many records are in your table.

2.) If you table isn't in DBF format, make it so.

3.) Create a new line shapefile (mine is called "bad_idea.shp")

4.) We need to make as many null geometries as there are records in your table. You can do so with the following Python code:

>>> insCursor = arcpy.da.InsertCursor("bad_idea","SHAPE@")
... for i in range(7):# change to the number of null geometries you want to make
...    myArray = arcpy.Array()
...    myPoint = arcpy.Point()
...    myArray.add(myPoint)
...    myLine = arcpy.Polyline(myArray)
...    insCursor.insertRow([myLine])

5.) Close down ArcGIS to release any locks on bad_idea.shp

6.) Delete "bad_idea.dbf" in file explorer

7.) Rename your original table (the one with the attributes you want to keep) to "bad_idea.dbf"

8.) ArcGIS won't open "bad_idea.shp" anymore (I'm not exactly sure why), but QGIS is more liberal with that sort of thing. Bring this diseased shapefile into QGIS and save a copy, say "bad_idea_copy.shp"

9.) Bring "bad_idea_copy.shp" into ArcGIS. It should have your original attribute table associated with null polyline geometries.

10.) Start editing.

11.) Select the feature from the attribute table for which you want to update the existing null geometry to a real geometry

12.) Start editing vertices (editing toolbar)

13.) From the edit vertices toolbar, select Continue Feature Tool

14.) Draw your new feature. This geometry is associated with the selected record in the attribute table.

15.) Repeat.

Have fun. I take no responsibility for any damage this method may cause.

Re: How do I copy attribute data to an existing shapefile?

DavidBollinger — Thu, 03 Dec 2015 18:29:16 GMT

$0.02 fwiw, if you're already in python... and already inserting records into a fc... then why not go one tiny step further and build something valid? iow, read the source attribute records, for each copy fields and create new fully attributed record into an empty fc, using some "dummy" (but valid) line segment that you can later edit.

Re: How do I copy attribute data to an existing shapefile?

DarrenWiens2 — Thu, 03 Dec 2015 18:34:41 GMT

Hmmm... Yes, all valid points.

edit: although, any workflow that includes creating null geometries is somewhat debatable as being "valid".

Re: How do I copy attribute data to an existing shapefile?

AlexandraDubovis — Thu, 03 Dec 2015 20:10:39 GMT

Eliza_J

I didn't see if you reply to Elizabeth Jarvie.

If you have a street segment feature class or shape file it can save you a lot of manual work.

Re: How do I copy attribute data to an existing shapefile?

Celeste_SuliinBurris — Thu, 03 Dec 2015 21:15:11 GMT

If the table has an address, you could geocode it, and then do a spatial join. If not, you are going to have a find or create a common attribute. How would you match them by hand?