tAddCRCRow

tAddCRCRow properties

Component family	Data Quality
Function	tAddCRCRow calculates a surrogate key based on one or several columns and adds it to the defined schema.
Purpose	Providing a unique ID helps improving the quality of processed data.
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. In this component, a new CRC column is automatically added.
		Built-in: The schema will be created and stored locally for this component only. 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 designs. Related topic: see Talend Studio User Guide.
	Implication	Select the check box facing the relevant columns to be used for the surrogate key checksum.
Advanced Settings	CRC type	Select a CRC type in the list. The longer the CRC, the least overlap you will have.
	tStat Catcher Statistics	Select this check box to collect log data at the component level.
Global Variables	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. 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. 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 is an intermediary step. It requires an input flow as well as an output.
Limitation	Due to license incompatibility, one or more JARs required to use this component are not provided. You can install the missing JARs for this particular component by clicking the Install button on the Component tab view. You can also find out and add all missing JARs easily on the Modules tab in the Integration perspective of your studio. For details, see https://help.talend.com/display/KB/How+to+install+external+modules+in+the+Talend+products or the section describing how to configure the Studio in the Talend Installation and Upgrade Guide.

Scenario: Adding a surrogate key to a file

This scenario describes a Job adding a surrogate key to a delimited file
schema.

Setting up the Job

Drop the following components: tFileInputDelimited, tAddCRCRow and tLogRow.
Connect them using a Main row
connection.

Configuring the input component

In the tFileInputDelimited
Component view, set the File Name path and all related properties in case
these are not stored in the Repository.
Create the schema through the Edit Schema
button, if the schema is not stored already in the Repository. Remember to set the data
type column and for more information on the Date pattern to be filled in,
visit http://docs.oracle.com/javase/6/docs/api/index.html.

Configuring the tAddCRCRow component

In the tAddCRCRow
Component view, select the check boxes of
the input flow columns to be used to calculate the CRC.

Notice that a CRC column (read-only) has been added at the end of the
schema.
Select CRC32 as CRC
Type to get a longer surrogate key.
In the Basic settings view of tLogRow, select the Print
values in cells of a table option to display the output data
in a table on the Console.

Job execution

Then save your Job and press F6 to execute
it.

An additional CRC Column has been added to the schema calculated on all previously
selected columns (in this case all columns of the schema).

Document get from Talend https://help.talend.com

Thank you for watching.

Docs 5.x

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tAddCRCRow – Docs for ESB 5.x