M2M AD301 Podręcznik Użytkownika Pobierz pdf (Strona 129)

Data Integration with Sybase Avaki Studio 117

Generator

A Generator operator produces a result set without input. Like an Iterator, a Gener-

ator lets you specify JavaScript expressions for initializing variables, updating vari-

ables, and testing for termination. Unlike an Iterator, a Generator does not accept

inputs. Like a Projection operator, a Generator allows you to specify the names and

types of the output columns, as well as JavaScript expressions for computing the val-

ues in each row.

When a Generator is first called, it executes the Initialize expression you supply to

initialize variables. On each call, Generator

1. Tests the termination condition

2. If the termination condition has not been met, it generates a row with the designated

schema by executing all of the user-specified JavaScript expressions

3. Executes the Increment expression you supply to update variables.

The output of the Generator is the sequence of rows created in these iterations.

Connections

The Generator operator takes zero input result sets. It produces exactly one output

result set whose schema is defined by the operator.

Required Connection

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M2M AD301 Podręcznik Użytkownika Strona 129