5
Frequently Asked Questions

This chapter provides answers to frequently asked questions about the Database adapter. This chapter discusses the following topics:

• Installation Questions

• Design Time Questions

• Runtime Questions

Installation Questions

The following questions address installation of the Database adapter.

What should I enter on the Database User Configuration screen during installation?

This information is used to find where the stored procedures generated through iStudio will be installed for application inbound messages. At runtime, the Database adapter uses this information to call a user-specified stored procedure. This user can be an existing user or a user created specifically for Oracle9iAS InterConnect.

Is it possible to edit the database configuration settings created during installation?

Edit the adapter.ini file located in the $ORACLE_HOME/oai/9.0.2/adapters/[AppType][Partition] directory.

See Also: Chapter 2, "Installation and Configuration"

How can I specify a listener port other than 1521?

Edit the db_bridge_schema<#>_port parameter.

See Also: Chapter 2, "Installation and Configuration"

Can I install multiple Database adapters on the same machine?

Using the Oracle Universal Installer, only one Database adapter can be installed in a single Oracle Home. However, copies of the Database adapter using the copyAdapter script available in the $ORACLE_HOME/oai/9.0.2/bin directory. Usage: copyAdapter dbapp1 dbapp2

The script will create a copy of the already installed Database adapter called dbapp1 with a name of dbapp2.

Design Time Questions

The following are design time questions for the Database adapter.

Where is the PL/SQL code exported through iStudio saved?

The PL/SQL code is save in the $ORACLE_HOME/oai/4.1/iStudio directory. iStudio allows any extension to be specified which is used to prefix the name of every SQL file generated through iStudio. The following convention is used in naming the SQL files:

<PrefixSpecifiedInIStudio>_<ApplicationName>_<BusinessObject>TYPES.sql
<PrefixSpecifiedInIStudio>_<ApplicationName>_<BusinessObject>.sql

What is the Returned IN Args feature in iStudio and how do I use it?

Please see "Returned In Arguments".

How do I export stored procedures to use with the Database adapter?

The following steps describe how to export procedures for the Database adapter.

1. Use iStudio and select Export from the File menu. The Export Stored Procedures dialog displays.

2. Select the root of the tree to select all stored procedures from all applications.

   Two files are created for each application and business object if a base name is selected. The <base name>_<application name>_<business object name>.sql file defines all stored procedures for all messages from the selected business object and application. The <base name>_<applicationname>_<business object name>TYPES.sql file defines all types used by the stored procedures in the first file.

If you do not want to export all stored procedures for all applications as this can take a while, select one or more applications. Only the stored procedures for those applications will be generated. You can also select messages based on the role; for example, if you select publish, then only publish messages will be generated. Or, you can choose to export the stored procedures for specific messages by selecting those messages in the tree.

See Also: "Runtime Questions"

Can database messages contain arrays of arrays?

The database does not allow arrays of arrays. Therefore, the application view of database messages should not contain arrays of arrays. For example, the application view of a database message can contain an array of Customers which each contained one Address. However, it can not contain an array of Customers which each contained an array of Addresses.

Runtime Questions

The following questions address runtime concepts for the Database adapter.

When I run start, I do not see anything happening - no log files are created and I don't see any messages in the console - how do I get back to the command prompt?

A start executable that is not the Oracle9iAS InterConnect start script must be running. This is dependent on what is in the PATH environment variable. Therefore, run the start script as follows:

Platform	Executable
UNIX	./start
Windows	Use the Service Panel.

Why do I get errors when trying to load PL/SQL code generated through iStudio?

Make sure you none of the PL/SQL reserved keywords are used in Oracle9iAS InterConnect messages. For example, for a Phone object contains the attributes areacode and number, a problem would occur because number is a reserved keyword in PL/SQL.

What are the steps to prepare a Database adapter that publishes events?

Before a Database adapter can publish events, some stored procedures need to be generated in iStudio.

See Also: "Design Time Questions"

iStudio will create two SQL scripts for a publish message; one with stored procedures and one with types. The types script name will end with TYPES.sql. Using any username, load the types scripts and the stored procedure script into the database.

When an event occurs, there are several PL/SQL methods that must be called to publish the event message. All of the methods reside in the <event business object> package which is created in the stored procedure SQL script. The first procedure that must be called is crMsg_<event name>_<event owner>_<event version>. It has two out arguments which are both of type number--the message id and the root data type id.

Next, populate the message with the correct data. For each non-primitive attribute that the message contains, there is a function called cr_<data type name>_<attribute name>. This function has one argument for each primitive attribute it contains and it takes the message id and the parent data type id. It returns a number which is the data type id. When all data types have been created, a procedure must be called to publish the message. This procedure is named pub_<event name>_<eventowner>_<event version>. This procedure has three arguments: the message id, the source application name, and the destination application name. The destination application name is ignored, so pass in whatever is applicable.

For example, an event in the Customer business object is called create. Application A publishes this event. The application view of this event contains an attribute called C of type cust. The cust type contains a name attribute which is a String and a loc attribute of type Location. The Location type contains a city attribute which is a String and a state attribute which is also a String. The following piece of code would publish a create event.

DECLARE 
  moid NUMBER; 
  aoid NUMBER; 
  custid NUMBER; 
  locid NUMBER; 
BEGIN 
  Customer.crMsg_create_TEST_V1(moid, aoid); 
  custid := Customer.cr_cust_c('Homer', moid, aoid); 
  locid := Customer.cr_Location_loc('Redwood Shores', 'CA', moid, custid); 
  Customer.pub_create_TEST_V1(moid, 'a', ''); 
END 

What are the steps to prepare a Database adapter that invokes procedures?

This is very similar to publishing events. All of the steps are the same until the final procedure call. The name is inv_<proc name>_<proc_owner>_<proc version> and has three IN arguments: the message id, the source application name, and a timeout. The timeout is how many seconds to wait for a response. The event also has as many OUT arguments as the procedure defined in iStudio has.

What are the steps to prepare a Database adapter that subscribes to events?

Before a Database adapter can subscribe to events, some stored procedures need to be generated in iStudio.

See Also: "Design Time Questions"

iStudio will create two SQL scripts for a subscribe message: one with stored procedures and one with types. The types script name will end with TYPES.sql. Under the same user name specified on the Database Configuration page during installation, load the types scripts and the stored procedure script into the database. A pre-existing user can be specified, but if a user name that does not exist is entered, that user must be created manually.

The DB adapter will call the procedure sub_<event name>_<event owner>_<event version> in the package <eventbusiness object> when a message is received. Add PL/SQL code in this method to perform whatever tasks are necessary when this kind of message is received. This code can be added in iStudio when creating the message, or modify the stored procedure SQL script before loading it into the database.

What are the steps to prepare a Database adapter that implements procedures?

The steps are very similar to subscribing to events. However, the procedure that the Database adapter will call is imp_<procname>_<proc owner>_<proc version>. This procedure will have OUT arguments corresponding to the OUT arguments in the procedure defined in iStudio. In addition to writing PL/SQL code to perform the necessary tasks, the OUT arguments must be filled in with correct values. Write this code in iStudio when creating the message, or modify the stored procedure SQL script before loading it into the database. If the start script is used to start the Database adapter, there is a way to determine if the Database adapter was started properly. This can be viewed in the oailog.txt file in the logs directory of the Database adapter.