Release 10.1A: OpenEdge Development:
Progress 4GL Reference

CONNECT statement

Allows access to one or more databases from within a Progress procedure.

Syntax 

CONNECT
  { 
    { physical-name | VALUE ( expression ) } [ options ] | options  
  }
  [ NO-ERROR ]

physical-name

The actual name of the database on disk. It can be a simple filename, relative pathname, or a fully qualified pathname, represented as an unquoted string, a quoted string, or a VALUE ( expression ). If you do not give a fully qualified pathname, Progress searches for the database relative to your current directory.

VALUE ( expression )

An expression (a constant, field name, variable name, or expression) whose value is a string representing the physical name of a database to connect.

options

One or more options, similar to those used to start Progress. Valid options are a subset of OpenEdge startup parameters. Note that parameters are case sensitive.

See OpenEdge Deployment: Startup Command and Parameter Reference for more information on OpenEdge startup parameters.

NO-ERROR

Suppresses errors in the act of connecting. This does not mean that all errors produced by the server are suppressed; only errors caused by the CONNECT statement itself. For example, if the server to which you are connecting runs out of resources, its error message will not be suppressed. If a CONNECT error occurs (for example, the database does not exist or is in use in single-user mode), error information is written to the ERROR-STATUS system handle.

You also can use the CONNECTED function to determine whether the CONNECT succeeded and then retrieve error messages from the ERROR-STATUS handle.

Examples

This procedure attempts to connect to databases mydb1 and mydb2 in single-user mode, with error suppression. You must connect to a database before you run a procedure that references it.

r-connct.p 
CONNECT mydb1 -1 -db mydb2 -1 NO-ERROR.

In the next example, assume database sports has not been previously connected, so the following r-cnct1.p procedure fails. At the start of execution, r-cnct1.p checks whether sports is connected. If sports is not connected, a run-time error occurs. As shown in the example, attempting to connect to sports within the procedure does not solve the problem. 

/* NOTE: this code does NOT work */

CONNECT sports -1.
FOR EACH sports.customer:
  DISPLAY customer.
END.

Instead, split r-cnct1.p into two procedures, as shown in r-dispcu.p and r-cnct2.p:

r-dispcu.p 
FOR EACH sports.customer:
    DISPLAY customer.
END.

r-cnct2.p 
CONNECT sports -1.
RUN "r-dispcu.p".

This time, database sports is connected before r-dispcu.p is invoked, so r-dispcu.p runs successfully.

Notes

1. Change the permissions of the OpenEdge client executable to rwsrwsr-x by typing chmod 6775 _progres.

2. Change the group of the client executable to match the group of the raw device (for example, /dev/rsd0d) and block special device (for example, /dev/sd0d).

3. Change the permissions of the raw and block special devices to "rw-rw----".

The disadvantage of this procedure is that all files produced within OpenEdge have the same group as the disk device. Consider the following:

See also

ALIAS function, CONNECTED function, CREATE ALIAS statement, CREATE CALL statement, DATASERVERS function, DBCODEPAGE function, DBCOLLATION function, DBRESTRICTIONS function, DBTYPE function, DBVERSION function, DELETE ALIAS statement, DISCONNECT statement, FRAME-DB function, LDBNAME function, NUM-DBS function, PDBNAME function, SDBNAME function

Copyright © 2005 Progress Software Corporation
 www.progress.com
Voice: (781) 280-4000
Fax: (781) 280-4095