Course 17 Procedure Call Expression скачать в хорошем качестве

Course 17 Procedure Call Expression

A procedure call expression enables the execution of function modules as well as of methods of an ABAP OO class in the backend system. You can also use this expression directly to execute procedures that are stored in a database. You use this expression to take advantage of the full functional power offered by the ABAP programming language when processing BRFplus business rules. You can do so in order to access routines for data validation, data conversion, or any other kind of data manipulation regardless of the degree of complexity of such routines. Values can be passed to the parameters of the called procedure by using a list of parameter mappings that are maintained for the expression. Once the called procedure has determined a result, it is returned to the result data object of the procedure call expression. If the procedure that you want to execute is stored in a database (stored procedure), you can directly access this kind of procedure without having to define a wrapper method manually in an ABAP OO class. This saves you programming effort and the number of steps in the execution path is reduced, thereby improving performance. Database Procedures In a procedure call expression, you can directly call a stored procedure that resides in the database. This helps you saving additional programming effort, as well as improving the performance of database accesses because there are fewer execution steps. A procedure is always assigned to one of the various database schemas that may exist in the database. Therefore, a fully qualified definition of the procedure to be used consists of the procedure's name plus the containing database schema. In the BRFplus workbench, the value help supports you in retrieving the desired procedure by offering matching procedures across the different schemas. In other words, although the schema is needed for identifying the database procedure, you do not need to delve too deeply into the database to find the object you are searching for. The database where the procedure to be called resides can either be the database that is associated with the system in which you execute the expression, or it can be a database that runs in a different system within your landscape. In the latter case, you have to set up a secondary database connection. This can be accomplished in the scope of the application to which the procedure call expression belongs.