Modification of field properties

All fields have properties, which are set when you create a table or feature class. In ArcGIS, the first properties you set for a field are its Field Name and Data Type. The other properties you set are dependent on the data type of the field.

You can change certain field properties after you create the table or feature class. For enterprise geodatabases, the properties you can change and how you change them depends on the database management system you use; you can only make changes that your database allows. For example, if your database does not allow you to change the length of a field in a table that contains data, you cannot change the field length through ArcGIS.


Depending on the data source, not all field properties may be available.

You can alter the following field properties:

  • Visible
  • Read Only
  • Field Name
  • Alias
  • Data Type
  • Allow NULL
  • Highlight
  • Number Format
  • Domain
  • Default Value
  • Precision
  • Scale
  • Length

Keep the following in mind when modifying field properties:

  • Highlight—Once enabled, the field is highlighted in the attribute table and attributes pane.
  • Allow NULL—Can only be set to false if the table is empty.
  • Data Type—Can only be changed if the table is empty.
  • Length—May be increased or decreased for empty tables. Can only be increased for tables with data.

You can access field properties from the Fields view for a feature class or table. Note that the field properties available will differ slightly depending on if the Fields view is accessed from a layer in the Contents pane or from a dataset in the Catalog pane.

Read more about how to create and manage fields.