Relating to my question about the split tool here, as suggested I ask a new question: is there any place with a list of invalid characters to use in a database in ArcGIS 10?

edit: It is in relation to the error I got before which is "The name starts with an invalid character". It didn't say where beyond that.

  • 1
    Clarify your question. Invalid where? column names? Indexes names? table names? actual row data? Jul 27, 2011 at 16:43
  • The error she received was "000361 : The name starts with an invalid character". This indicates an invalid table or field name. Emily, have you tried renaming the fields in the shape file to contain only alphanumerics and to not start with numbers? I don't know if an underscore is allowed at the beginning of a column name in a geoDB, and can't test at the moment.
    – user3461
    Jul 27, 2011 at 16:50
  • All of the fields start with a lowercase alphabetical character.
    – Emily
    Jul 27, 2011 at 17:04
  • what are the names in lowercase?
    – Mapperz
    Jul 27, 2011 at 17:45
  • What database format are you using? shapefile, personal gdb, file gdb, SDE? Each one has its own set of potential possibilities. Jul 27, 2011 at 20:02

4 Answers 4


I am guessing you are referring to "Reserved Words" and special characters. Take a look at the following links, but ultimately reserved words and reserved characters are going to be more DATABASE (shapefile, MS Access, Oracle, SQL Server, etc) dependent vs ARCGIS dependent.

ESRI KB- What characters should not be used in ArcGIS for field names and table names?

ESRI Forum- .dbf files/naming conventions

ESRI Blog- Words (by Reservation Only)


I don't know about a definitive, complete list, because it depends on the DBMS, but ArcObjects and arcpy/arcgisscripting have functions for helping you write valid SQL queries and validate table/field names. ArcObjects also has DBMS-specific invalid character lists.

GP methods:

ArcObjects methods:


From personal experience you should make sure that names (1) begin with a letter, (2) contain no spaces, (3) contain 7 or fewer characters, and (4) only use alphanumeric characters.

  • Are you referring to geodatabases other then PGDB / FGDB? Because in the desktop environment PGDB / FGDB you can begin table or a feature class name with an underscore, use an underscore anywhere in the name. Feature Class and Table names in an FGDB can have 160 characters and field names 64 characters. No special limitation on the number of numeric characters other that the names cannot begin with a number. Jul 28, 2011 at 13:08

Remember, too, that ESRI appends to names you give columns etc, and if you don't pay attention, you could go over the permitted width for columns, table names etc. I think 22 is the magic number on that. also, this will depend on the RDBMS you se, and each one will be different.

  • I've never heard of this but would be interested in learning more. Can you provide an example of what you are describing? Or link to any documentation for others to get a better understanding? Also, an explanation of where the 22 character limit comes from? Jul 28, 2011 at 16:07
  • I think it is a limitation on Oracle, in that you can only have column names of 30 cahrs. However, the other day, I was creating am mosaic, it had a long field name, which was rejected. On delving deeper, I found that ArcGIS was appending characters to the column/field name and this was taking it over the Oracle limit. By elimination, and studying what was being appended, I came to the 22 char rule.
    – Hairy
    Aug 1, 2011 at 7:28

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