How to join thousands of rows (date data) from a CSV to a small amount of rows (location county data) in Arc Map Pro

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09-23-2019 11:24 AM
MatthewKatz
New Contributor

I'm not sure I am asking the question correctly, so I will describe my situation. I have a polygon boundary layer with 64 Colorado counties. I also have a CSV with roughly a thousand (1,000) rows that describe drought data for each county along with dates. So it shows changes in drought conditions per county by year from 2000-2019. I would like to show on a map changes in drought conditions as time progresses, and I can do this by geocoding the table, symbolizing the point centroids with graduated colors, and then using the time slider feature in ArcMap Pro. However, because I am using geocoding, these depicts points, but I would prefer to show the county polygons with colors. I am having trouble because since there is only 64 counties, and 1,000+ records, I cannot use the join tool. Is there another way to join, or combine all my data with the polygon shapefiles so I can depict change in drought conditions by colors of polygons (instead of points centroids)?

Thanks!

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6 Replies
AdrianWelsh
MVP Honored Contributor

Matthew,

Have you tried a spatial join to see if that works?

Spatial Join—Help | ArcGIS Desktop 

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MatthewKatz
New Contributor

Can I do a spatial join with a table to a county polygon layer? I don't see the option. All I see for the target and join features are layers within my maps.

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AdrianWelsh
MVP Honored Contributor

Matthew Katz, oh I thought you had made points from the geocoding you mentioned earlier. No, you cannot spatial join from a table. First make the points, geocoded (make sure they are saved as feature classes). I am guessing they're placed in the centroid of the county? Then try the spatial join. But, I'm not sure if it will make a new polygon for each new point. You may have to play around with it some (I don't have a sample set in front of me to test).

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MatthewKatz
New Contributor

I have geocoded the points and have utilized a spatial join. It seems to only have data from one year or one set of values because when I use the time slider, all the data is absent besides for the last year,

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AdrianWelsh
MVP Honored Contributor

Yeah, I had a feeling that was going to happen. Ok, I think the best tool to use is:

Make Query Table. This should make a table/layer based on your features and your data table. You can then export the table to a feature class and it should be solid.

I haven't tried this but I want to with real data...

To see a representation somewhat, there is better documentation in the ArcMap article instead of Pro:

Examples of queries with the Make Query Table tool—Help | ArcGIS for Desktop 

Try that and I think it should solve your problem.

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