Fundamentals of adding and deleting fields

You can add or remove fields from a table or feature class. Most likely, you'll add or remove fields from data that you personally manage.

You can add or remove fields as long as the following conditions are met:

Large organizations typically have databases with well-defined schemas that outline the contents, including fields, of the database. Unless you manage the database, it is unlikely that you'll be able to add or remove fields.

To add a new field, you need to specify the field's data type and any required properties. For example, you need to specify length for string fields and precision and scale for numeric fields in ArcSDE geodatabases.

The Add Field dialog box only lists the field types and properties supported by the particular data source to which you're adding the field. For example, you won't see the BLOB field type in the Add Field dialog box unless you are working with a geodatabase. In addition, if you are adding a numeric field to a personal or file geodatabase, you won't see the precision and scale properties since they only apply to ArcSDE geodatabases.

Follow these links to learn more about fields and working with them in various data sources:

Defining fields in geodatabase tablesGeodatabase field data typesCoveragesShapefiles or dBASE tables

Field naming guidelines

Field names need to adhere to certain conventions for them to be valid. Keep the following guidelines in mind when you name a field:


Remember that you can set a field alias if you need special characters, spaces, additional length, and so on. Aliases do not have to adhere to the limitations of the database, so you can give names to fields that are more descriptive than their actual field name. For example, you might specify an alias of Date of deed for a field stored in the geodatabase as DEED_DATE.

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