Use Custom Functions

A Function is a Mapping Services object that represents a function written in a program language (such as C, Java or SQL). These are functions that you add to the standard set of DML functions that are available in Mapping Services after it is installed.

Develop

You can develop your own functions, and you can also use add-on functions provided by Axway.

Use

For C function and Java function objects, the file containing the executable code and the data that is bound to the function resides on the Map Engine server.

For SQL function objects, in Mapping Services you enter an SQL SELECT statement in the dedicated SQLExpression text of the function editor.

Functions take an input value and produce a return value.

You use functions in the DML expressions in Maps.

Each Function object is stored in a Mapping Services folder. To reference a function from a DML expression, you use the unique logical name of the function. Each reference instructs the software to consult the relevant property and parameter definitions in the Function object.

You can use the following types of Functions:

Custom Function Type Development environment Description

C (developed in C)

Map Engine server

Functions that you develop and compile on the Map Engine Server in C programming language.

To use the C Function, the function must be implemented in a dynamic library that resides on the execution server.

To use the Function in a Mapping Services object, you must define its general properties and parameters in Mapping Services.

To execute the Function, the software matches the parameter defined in Mapping Services with the ones on the Map Engine server.

Java (developed in Java)

Map Engine server

Functions that you develop on the Map Engine server in Java programming language.

To use the Java Function, the function must be implemented in a .jar on the execution server.

To use the Function in a Mapping Services object, you must define its parameters in Mapping Services.

To execute the Function, the software matches the parameters defined in Mapping Services with the ones on the Map Engine server.

Optionally you can use Java Functions to return values via:

  • JDBC
  • RFC interface to SAP

SQL (SQL SELECT instruction)

Mapping Services Function object

Database Functions are SQL instructions that you define in Mapping Services.

The SQL Function object definition includes an SQL SELECT instruction.

Each SQL Function can retrieve one value from a database. SQL Functions require a JDBC channel. This channel provides the middleware that the software uses to connect to and retrieve a value from a database.

Each Function object is a self-contained and reusable unit that you create, access, and work with in a work folder.

Related topics

Extended Objects

Create Custom Functions

Develop a Custom Function in C

Develop a Custom Function in Java

Develop an SQL Custom Function

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