tExtractDynamicFields – Docs for ESB 5.x

Component family

Processing/Fields

Function

tExtractDynamicFields extracts columns from a
dynamic schema to a standard schema.

Purpose

tExtractDynamicFields allows you to parse a
Dynamic column to create standard output columns.

Basic settings

Schema and Edit Schema

A schema is a row description, it defines the number of fields to be processed
and passed on to the next component. The schema is either Built-in or stored remotely in the Repository.

Since version 5.6, both the Built-In mode and the Repository mode are
available in any of the Talend solutions.

Click Edit schema to make changes to the schema. If the
current schema is of the Repository type, three options are
available:

Click Sync columns to retrieve the schema from
the previous component in the Job.

This component offers the advantage of the dynamic schema feature. This allows you to
retrieve unknown columns from source files or to copy batches of columns from a source
without mapping each column individually. For further information about dynamic schemas,
see Talend Studio
User Guide.

This dynamic schema feature is designed for the purpose of retrieving unknown columns
of a table and is recommended to be used for this purpose only; it is not recommended
for the use of creating tables.

Built-in: You create the schema and store it
locally for the relevant component. Related topic: see Talend Studio User
Guide.

Repository: The schema already exists and is
stored in the Repository, hence can be reused in various projects and Job
flowcharts. Related topic: see Talend Studio User
Guide.

Advanced settings

tStatCatcher Statistics

Select this check box to gather the Job processing metadata at a Job level as
well as at each component level.

Global Variables

ERROR_MESSAGE: the error message generated by the
component when an error occurs. This is an After variable and it returns a string. This
variable functions only if the Die on error check box is
cleared, if the component has this check box.

NB_LINE: the number of rows read by an input component or
transferred to an output component. This is an After variable and it returns an
integer.

A Flow variable functions during the execution of a component while an After variable
functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl +
Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio
User Guide.

Usage

This component handles flow of data therefore it requires input and output
components.

Log4j

The activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User
Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Limitation

n/a