Understanding Handles
In JD Edwards EnterpriseOne table I/O operations, the term handle refers to a type of file pointer. This file pointer connects the application or Universal Batch Engine (UBE) with the JD Edwards EnterpriseOne database middleware that communicates with the database manager. Handles point to a database table, and they are references to an address within the database middleware. Handles enable you to perform these operations, which cannot be performed using non-handle table I/O operations:
Concurrently open multiple instances of a single table or business view.
Open a table or business view in an environment other than the environment to which you are signed in.
This feature is particularly helpful when you receive an upgrade to JD Edwards EnterpriseOne software or when you need to convert data from another system into JD Edwards EnterpriseOne software.
Pass handles into a form, named event rule, or business function so that you do not need to open a table or business view more than once.
Note: You cannot use handles in transaction processing.
If you pass a handle to a form or a named event rule, a HANDLE data item must be included as a member in the data structure for the form or named event rule. In the form interconnect or business function call, you must assign a handle value from the event rules to the HANDLE data structure member. You can use this handle in the form or named event rule in the same way that you use any other table I/O handle.
You must explicitly open and close handles, unlike other table I/O operations in which the system implicitly opens or closes the table for you. You must open a handle before you can use it. All of the table I/O operations, except Open, work the same for handles as they do for tables and business views. When you are finished using a handle, you must explicitly close it. Close the handle in the same way that you close a table or business view, except select the Handle option.
In order to use handles in table I/O event rules, you must:
Define the handle in the data dictionary.
Create a handle variable in event rules.
Open the handle explicitly.
You might be able to find an existing handle for the table I/O. Whether you use an existing handle or create a new handle, you must create a handle variable in Event Rules Design. Create a handle variable in the same way that you create other variables. You can use any scope that is necessary.
After you create a handle variable, you must explicitly open the handle. Then, after performing the required table I/O, you must explicitly close it.