PRB: "The database must be opened exclusively" Multiuser Error
ID: Q130659
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The information in this article applies to:
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Microsoft Visual FoxPro for Windows, versions 3.0, 5.0, 5.0a
SYMPTOMS
In a multiuser situation, when you perform tasks that affect the contents
of a database (.DBC file), the error "The database must be opened
exclusively" is displayed.
CAUSE
The command requires exclusive access to the database. Several commands
that create or modify database objects require that the database not be
shared--at design time or run time.
This error may also occur at run time in an application or EXE if you have
included the database(s) in the project. By including the database(s) in
the project, you have caused them to be read-only, and you will not be able
to properly validate the database. In this situation, it is possible for
ISE CLUSIVE() to return a .T. (true) value and still get the error message
described above.
WORKAROUND
If you receive the error "The database must be opened exclusively" at
design time, all developers must close the database before you can proceed.
To prevent this error from occurring at run time when manipulating views or
connections, create a local database for each user. All users will have
exclusive access to their database, and will also be able to update the
table records contained in a centralized, shared database.
To verify whether or not a database is open exclusively, use the
ISEXCLUSIVE() function. The syntax for the ISEXCLUSIVE() function is:
ISEXCLUSIVE([cTableAlias | nWorkArea | cDatabaseName [, nType]])
When the nType parameter has a value of 2, the function returns the
exclusive status for a database. The following example code makes sure the
database is open exclusively before using the INDEX ON command:
CLOSE ALL
OPEN DATABASE SYS(2004)+"SAMPLES\DATA\TESTDATA"
SELECT 0
USE CUSTOMER
IF ISEXCLUSIVE('testdata',2)
INDEX ON CITY TAG CITY
ELSE
=MESSAGEBOX("Database must be opened Exclusively")
ENDIF
CLOSE DATABASE
NOTE: The above code uses CLOSE ALL to close all the files so that the
database can be opened but not selected, making the CLOSE DATABASE command
useless. Of course using CLOSE DATABASE ALL might not be helpful if only
one database needs to be closed. Therefore, issue the following code to
select a certain database to close and reopen:
SET DATABASE TO <dbc name>
CLOSE DATABASE
OPEN DATABASE <dbc name> EXCLUSIVE
This ensures that the correct database container is selected, closed, and
reopened.
STATUS
This behavior is by design.
MORE INFORMATION
If a view or a table contained in a database is open for shared use, the
database is also shared. Therefore, all multiuser applications require that
a database be shared.
However, commands that directly relate to the database (.DBC file)
structure and commands that involve the creation or deletion of objects
require exclusive use of the database. These commands include:
CREATE TABLE
MODIFY STRUCTURE
ALTER TABLE
ADD TABLE
RENAME TABLE
CREATE SQL VIEW
MODIFY VIEW
DELETE VIEW
RENAME VIEW
CREATE CONNECTION
MODIFY CONNECTION
DELETE CONNECTION
RENAME CONNECTION
INDEX ON && You can however use INDEX ON on a view
DELETE TAG
CREATE TRIGGER
DELETE TRIGGER
APPEND PROCEDURES
COPY PROCEDURES
MODIFY PROCEDURE
COMPILE DATABASE
PACK DATABASE
VALIDATE DATABASE
Additional query words:
denied
Keywords : kbnetwork kbprg FxprgMultiuser
Version : 3.0
Platform : WINDOWS
Issue type : kbprb