Starting Database Trace in a PowerBuilder application
In a PowerBuilder application that connects to a database, you
must specify the required connection parameters in the appropriate
script. For example, you might specify them in the script that opens
the application.
To trace a database connection in a PowerBuilder script, you
specify the name of the DBMS preceded by the word trace and a single
space. You can do this by:
-
Copying the PowerScript DBMS trace syntax from the Preview
tab in the Database Profile Setup dialog box into your
script -
Coding PowerScript to set a value for the DBMS property of
the Transaction object -
Reading the DBMS value from an external text file
For more about using Transaction objects to communicate with a
database in a PowerBuilder application, see Using
Transaction Objects in Application Techniques.
Copying DBMS trace syntax from the Preview
tab
One way to start Database Trace in a PowerBuilder application
script is to copy the PowerScript DBMS trace syntax from the Preview
tab in the Database Profile Setup dialog box into your script,
modifying the default Transaction object name (SQLCA) if
necessary.
As you complete the Database Profile Setup dialog box in the
development environment, PowerBuilder generates the correct connection
syntax on the Preview tab for each selected option, including Generate
Trace. Therefore, copying the syntax directly from the Preview tab
ensures that it is accurate in your script.
To copy DBMS trace syntax from the Preview tab into your
script:
-
On the Connection tab (or System tab in the case of OLE DB)
in the Database Profile Setup dialog box for your connection,
select the Generate Trace check box to turn on Database
Trace.For instructions, see Starting Database Trace in
the development environment. -
Click Apply to save your changes to the Connection tab
without closing the Database Profile Setup dialog box. -
Click the Preview tab.
The correct PowerScript connection syntax for the Generate
Trace and other selected options displays in the Database
Connection Syntax box. -
Select the SQLCA.DBMS line and any other syntax you want to
copy to your script and click Copy.PowerBuilder copies the selected text to the
clipboard. -
Click OK to close the Database Profile Setup dialog
box. -
Paste the selected text from the Preview tab into your
script, modifying the default Transaction object name (SQLCA) if
necessary.
Coding PowerScript to set a value for the
DBMS property
Another way to start the Database Trace tool in a
PowerBuilder script is to specify it as part of the DBMS property of
the Transaction object. The Transaction object is a special nonvisual
object that PowerBuilder uses to communicate with the database. The
default Transaction object is named SQLCA, which stands for SQL
Communications Area.
SQLCA has 15 properties, 10 of which are used to connect to your
database. One of the 10 connection properties is DBMS. The DBMS
property contains the name of the database to which you want to
connect.
To start the Database Trace tool by specifying the DBMS
property:
-
Use the following PowerScript syntax to specify the DBMS
property. (This syntax assumes you are using the default
Transaction object SQLCA, but you can also define your own
Transaction object.)1SQLCA.DBMS = "trace DBMS_name"For example, the following statements in a PowerBuilder
script set the SQLCA properties required to connect to an Adaptive
Server database named Test. The keyword trace in the DBMS property
indicates that you want to trace the database connection.12345SQLCA.DBMS = "trace SYC"SQLCA.database = "Test"SQLCA.logId = "Frans"SQLCA.LogPass = "xxyyzz"SQLCA.ServerName = "Tomlin"
Reading the DBMS value from an external
text file or the registry
As an alternative to setting the DBMS property in your
PowerBuilder application script, you can use the PowerScript
ProfileString function to read the DBMS value from a specified section
of an external text file, such as an application-specific
initialization file, or from an application settings key in the
registry.
The following procedure assumes that the DBMS value read from
the database section in your initialization file uses the following
syntax to enable database tracing:
|
1 |
DBMS = trace DBMS_name |
To start the Database Trace tool by reading the DBMS value
from an external text file:
-
Use the following PowerScript syntax to specify the
ProfileString function with the DBMS property:1SQLCA.DBMS = ProfileString (file, section, variable, default_value)For example, the following statement in a
PowerBuilder script reads the DBMS value from the [Database]
section of the APP.INI file:1SQLCA.DBMS=ProfileString("APP.INI", "Database", "DBMS","")For how to get a value from a registry file instead, see
Getting values from the
registry.