Add new columns to a shapefiles attribute table using join an relate function in arcmap 10.4
To join or add data to a new column on a shapefile using Esri’s ArcMap 10.4 you need to first have a .csv file that has a relation to the column that is in your current shapefile. That is, if your arcmap shapefile has a column named IDs your CSV file has to have an ID column to be able to match with the values of the column you want to base your join on. Below are the steps to be able to join and relate data onto your shapefile.
Step 1 – Select the shapefile layer using Arc catalogue and drop it into your data view.
Step 2 – Choose your CSV file and drop it into data view.
Step 3 – On your contents view select your shapefile layer and right click Join and Relates ->Join
Step 4 – Select the field from your shapefile in which the join will be based on. Eg BSI_CODE
Step 5 – Find the table to join into the layer. IE the csv file
Step 6 – Select the field in the table to base the join on. Eg. BSI_CODE
Step 7 – Click ok and open your shapefiles attribute table. You should see the new column/columns imported from the CSV file with the matching values.
Step 8 – IMPORTANT – Make sure once the new layer is added to the data view that you right click and select export data and save it as a new shapefile.