Q129866: Use of Long Names

Article: Q129866
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0
Operating System(s): 
Keyword(s): 
Last Modified: 10-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, version 3.0 
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SUMMARY
=======

Visual FoxPro for Windows allows long names for tables and fields within a
database. Names of up to 128 characters are allowed.

MORE INFORMATION
================

The long name for the table is not the actual file name as displayed in file
manager but an additional name for the table stored in the database container.
So there are two table names, and you can use either one to open the table when
the database is opened. However, there is only one field name per field.

The DISPLAY TABLES command lists the long table names and their actual file
names. Use ADBOBJECT(arrayname,'table') to put the table names into an array.
The array will contain only one name per table. If a table does not have a long
name, the array will contain its filename. Filenames are only eight characters
under Windows and Windows for Workgroups. In operating systems such as Windows
NT, the actual file names can be longer than eight characters.

The Visual FoxPro Help File lists the following rules for names:

1. Names can only contain letters, underscores, and numbers.

2. Names must begin with a character or an underscore.

3. Names can have up to 254 characters

4. Avoid use of reserved words.

Long names for fields and tables do not necessarily follow these rules. Long
table names can contain spaces but long field names cannot. The following
creates a table named "Long table name."

     OPEN DATABASE SYS(2004)+"samples\data\testdata.dbc"
     CREATE TABLE longname NAME "Long table name" (longfieldname c(20))

NOTE: The USE "long table name" command opens the table, but the name is
displayed with underscores instead of spaces in the View Window and in SELECT
commands, which require underscores instead of spaces.

Names of tables and fields abide by Rule 2. Rule 3 applies to variable names but
not to long table and field names, which can be no longer than 128 characters.
This is documented in the help file under the "long table names" and "fields,
naming" topics.

When copying a table with a long table name and long field names, the long table
name is dropped and long field names are truncated to 10 characters. If the
first 10 characters of two fields are identical the second field will be
truncated to nine characters and the number 2 will be added at the end. The long
names are dropped or truncated because the COPY TO command does not place the
new table in the database, and long names are only allowed when a table is part
of a database.

The following copies the table that was created above:

     COPY TO newtable

No long table name exists because newtable is not part of the database, and the
longfieldname field is truncated to "longfieldn.

REFERENCES
==========

NOTE: For more information about the RENAME TABLE command that allows changes to
be made to the long name of a table, please see the following article in the
Microsoft Knowledge Base:

  Q129098 How to Change a Table's Name

Also see the "Microsoft Visual FoxPro Developer's Guide," chapter 7, "Naming a
Table" and "Naming Fields" sections.

Additional query words: VFoxWin 3.00

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Keywords          :  
Technology        : kbVFPsearch kbAudDeveloper kbVFP300
Version           : WINDOWS:3.0

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