tExtractPositionalFields - 6.3

Talend Open Studio for Big Data Components Reference Guide

EnrichVersion
6.3
EnrichProdName
Talend Open Studio for Big Data
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Function

tExtractPositionalFields generates multiple columns from one column using positional fields.

Purpose

tExtractPositionalFields allows you to use a positional pattern to extract data from a formatted string.

tExtractPositionalFields properties

Component family

Processing/Fields

 

Basic settings

Field

Select an incoming field from the Field list to extract.

 

Ignore NULL as the source data

Select this check box to ignore the Null value in the source data.

Clear this check box to generate the Null records that correspond to the Null value in the source data.

 

Customize

Select this check box to customize the data format of the positional file and define the table columns:

Column: Select the column you want to customize.

Size: Enter the column size.

Padding char: Type in between inverted commas the padding character used, in order for it to be removed from the field. A space by default.

Alignment: Select the appropriate alignment parameter.

 

Pattern

Enter the pattern to use as basis for the extraction.

A pattern is length values separated by commas, interpreted as a string between quotes. Make sure the values entered in this fields are consistent with the schema defined.

 

Die on error

Clear the check box to skip any rows on error and complete the process for error-free rows. When errors are skipped, you can collect the rows on error using a Row > Reject link.

 

Schema and Edit Schema

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

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

  • View schema: choose this option to view the schema only.

  • Change to built-in property: choose this option to change the schema to Built-in for local changes.

  • Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the [Repository Content] window.

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

 

 

Built-In: You create and store the schema locally for this component only. Related topic: see Talend Studio User Guide.

 

 

Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. Related topic: see Talend Studio User Guide.

Advanced settings

Advanced separator (for number)

Select this check box to change the separator used for numbers. By default, the thousands separator is a comma (,) and the decimal separator is a period (.).

 

Trim Column

Select this check box to remove leading and trailing whitespace from all columns.

 

Check each row structure against schema

Select this check box to check whether the total number of columns in each row is consistent with the schema. If not consistent, an error message will be displayed on the console.

 

tStatCatcher Statistics

Select this check box to gather the processing metadata at the 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.

The NB_LINE variable is not available to the Map/Reduce version.

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. It allows you to extract data from a delimited field, using a Row > Main link, and enables you to create a reject flow filtering data which type does not match the defined type.

Log4j

If you are using a subscription-based version of the Studio, 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

Related scenario

For a related scenario, see Scenario: Extracting name, domain and TLD from e-mail addresses.