WebSphere Message Broker, Version 8.0.0.7 Operating Systems: AIX, HP-Itanium, Linux, Solaris, Windows, z/OS

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Join

The Join transform joins elements from two or more inputs. The inputs can be arrays or single elements, which can be merged using nested transforms to create a single output. The target element can be an array or single element but must be a complex type.

The Cardinality property page on the transform allows you to indicate which input array to iterate over. When there are no more elements left in this input array, the transform ends. The Cardinality page determines which indexes from which input arrays are used. The size of the output array is equal to the size of this input array.

The Join expression determines which array elements are joined to which other array elements. For example, to join the first element of the first array with the first element of the second array, you set a join condition that matches based on index. If you do not specify a Join expression, the join matches the first element of the first array with all elements of the second array, and then it matches the second element of the first array with all elements of the second array, and so on. For example, if you match on index and you have two array inputs, each having three elements, the result will be three output elements. However, if you do not set a join expression, the result will be nine elements.

Iteration is performed over each array input in unison (for example, first operate on index 1 over all inputs and output, then operate on index 2 over all inputs and output, and so on). The output array size is equal to the size of the input array that is chosen for iteration, minus any elements that are filtered out from the cardinality properties page

The input arrays can be of different sizes. In this case, iteration occurs as follows:
  • If an input array is larger than the size of the input array chosen for iteration, the iteration stops when the end of the input array chosen for iteration is reached.
  • If an input array is smaller than the size of the input array chosen for iteration, when the end of the smaller array is reached, subsequent iterations ignore transforms defined on the smaller array.

For information about the Mapping node, see Mapping node.

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        Last updated: 2016-05-23 14:48:31


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