how to change null value to specific numbers in arcgis

Question

I have a Excel file showing annual precipitation and I add it on arcmap. When I tried to check it's attribute table the field calculator is passive. I want to change all the Null value to specific number for analysis. how can i solve it plz.

Answer 1

If your data is an Excel table to start with, you can do a global search and replace in Excel before importing to ArcGIS.

Answer 2

if you import it to a gdb you can run calcField like so

1. open the Calculate Field tool
2. set the input table, field name (your date field), expression type to PYTHON

3. set the expression to

   x(!your_date_field!)
   

4. put this code into the code block (update my dec 31 1981 to your desired date)

   import datetime
   def x(v):
   if v is None:
     return datetime.datetime(1981, 12, 31)
   else:
     return v
   

Answer 3

If you want to be able to edit the file directly in ArcMap, you can also save your .xls as a .dbf before importing it.

Answer 4

Try this method :

1. Import your Excel sheet to ArcMAp
2. Export the sheet to dbf
3. Go to table properties of dbf
4. select Definition query => click Query Builder
5. Select the field with Null values then Click "Is" Button
6. Click "Get Unique Values and select Null
7. Now you can use Field Calculator to change Null.

sample : "City" IS NULL