August 17, 2023

tBigQueryOutput – Docs for ESB 5.x

tBigQueryOutput

tBigQueryOutput_icon32_white.png

Warning

This component will be available in the Palette of the studio on the condition that you have subscribed to
one of the Talend solutions with Big
Data.

tBigQueryOutput Properties

Component family

Big Data / Google BigQuery

 

Function

This component writes the data it receives in a user-specified
directory and transfers the data to Google BigQuery via Google Cloud
Storage.

Purpose

This component transfers the data provided by its preceding
component to Google BigQuery.

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:

  • 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.

 

Property type

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.

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

 

Local filename

Browse to, or enter the path to the file you want to write the
received data in.

 

Append

Select this check box to add rows to the existing data in the file
specified in Local filename.

Connection

Client ID and Client
secret

Paste the client ID and the client secret, both created and viewable on the API Access tab
view of the project hosting the BigQuery service and the Cloud Storage service you need to
use.

To enter the client secret, click the […] button next
to the client secret field, and then in the pop-up dialog box enter the client secret
between double quotes and click OK to save the
settings.

 

Project ID

Paste the ID of the project hosting the BigQuery service you need to use.

The default ID of this project can be found in the URL of the Google API Console, or by
hovering your mouse pointer over the name of the project in the BigQuery Browser
Tool.

 

Authorization code

Paste the authorization code provided by Google for the access you are building.

To obtain the authorization code, you need to execute the Job using this component and
when this Job pauses execution to print out an URL address, you navigate to this address to
copy the authorization code displayed.

 

Dataset

Enter the name of the dataset you need to transfer data to.

 

Table

Enter the name of the table you need to transfer data to.

If this table does not exist, select the Create the table if it doesn’t exist check
box.

 

Action on data

Select the action to be performed from the drop-down list when
transferring data to the target table. The action may be:

  • Truncate: it empties the
    contents of the table and repopulates it with the
    transferred data.

  • Append: it adds rows to
    the existing data in the table.

  • Empty: it populates the
    empty table.

Google storage configuration

Access key and Secret key

Paste the authentication information obtained from Google for making requests to Google
Cloud Storage.

To enter the secret key, click the […] button next to
the secret key field, and then in the pop-up dialog box enter the password between double
quotes and click OK to save the settings.

These keys can be consulted on the Interoperable Access tab view under the Google Cloud
Storage tab of the project.

 

Bucket

Enter the name of the bucket, the Google Cloud Storage container, that holds the data to
be transferred to Google BigQuery.

 

File

Enter the directory of the data stored on Google Cloud Storage and to be transferred to
BigQuery.

If the data is not on Google Cloud Storage, this directory is used as the intermediate
destination before the data is transferred to BigQuery.

  Header

Set values to ignore the header of the transferred data. For
example, enter 0 to ignore no
rows for the data without header and set 1 for the data with header at the first row.

 

Die on error

This check box is cleared by default, meaning to skip the row on
error and to complete the process for error-free rows.

Advanced settings

token properties File Name

Enter the path to, or browse to the refresh token file you need to use.

At the first Job execution using the Authorization code
you have obtained from Google BigQuery, the value in this field is the directory and the
name of that refresh token file to be created and used; if that token file has been created
and you need to reuse it, you have to specify its directory and file name in this
field.

With only the token file name entered, Talend Studio considers the directory of that token file
to be the root of the Studio folder.

For further information about the refresh token, see the manual of Google BigQuery.

 

Field Separator

Enter character, string or regular expression to separate fields for the transferred
data.

  Create directory if not exists

Select this check box to create the directory you defined in the File field for Google Cloud Storage, if it does not exist.

Custom the flush buffer size

Enter the number of rows to be processed before the memory is freed.

 

Check disk space

Select this check box to throw an exception during execution if
the disk is full.

 

Encoding

Select the encoding from the list or select Custom and
define it manually. This field is compulsory for database data handling.

 

tStatCatcher Statistics

Select this check box to collect the log data at the 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.

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 is an output component used at the end of a Job. It receives
data from its preceding component such as tFileInputDelimited, tMap or tMysqlInput.

Limitation

N/A

Scenario: Writing data in BigQuery

This scenario uses two components to write data in Google BigQuery.

use_case-tbigqueryoutput1.png

Linking the components

  1. In the Integration perspective
    of Talend Studio,
    create an empty Job, named WriteBigQuery for example, from the Job Designs node in the Repository tree view.

    For further information about how to create a Job, see the Talend Studio User
    Guide
    .

  2. Drop tRowGenerator and tBigQueryOutput onto the workspace.

    The tRowGenerator component generates the
    data to be transferred to Google BigQuery in this scenario. In the
    real-world case, you can use other components such as tMysqlInput or tMap in the
    place of tRowGenerator to design a
    sophisticated process to prepare your data to be transferred.

  3. Connect them using the Row > Main
    link.

Preparing the data to be transferred

  1. Double-click tRowGenerator to open its
    Component view.

    use_case-tbigqueryoutput2.png
  2. Click RowGenerator Editor to open the
    editor.

  3. Click Button_Plus.png three times to add three rows in the Schema table.

  4. In the Column column, enter the name of
    your choice for each of the new rows. For example, fname, lname and
    States.

  5. In the Functions column, select TalendDataGenerator.getFirstName for the
    fname row, TalendDataGenerator.getLastName for the lname row and TalendDataGenerator.getUsState for the States row.

  6. In the Number of Rows for RowGenerator
    field, enter, for example, 100 to define
    the number of rows to be generated.

  7. Click OK to validate these
    changes.

Configuring the access to BigQuery and Cloud Storage

Building access to BigQuery

  1. Double-click tBigQueryOutput to open its
    Component view.

    use_case-tbigqueryoutput3.png
  2. Click Sync columns to retrieve the schema
    from its preceding component.

  3. In the Local filename field, enter the
    directory where you need to create the file to be transferred to
    BigQuery.

  4. Navigate to the Google APIs Console in your web browser to access the
    Google project hosting the BigQuery and the Cloud Storage services you need
    to use.

  5. Click the API Access tab to open its view.

  6. In the Component view of the Studio,
    paste Client ID, Client secret and Project ID from the API Access tab view
    to the corresponding fields, respectively.

  7. In the Dataset field, enter the dataset
    you need to transfer data in. In this scenario, it is documentation.

    This dataset must exist in BigQuery. The following figure shows the
    dataset used by this scenario.

    use_case-tbigqueryoutput4.png
  8. In the Table field, enter the name of the
    table you need to write data in, for example, UScustomer.

    If this table does not exist in BigQuery you are using, select Create the table if it doesn’t exist.

  9. In the Action on data field, select the
    action. In this example, select Truncate to
    empty the contents, if there are any, of target table and to repopulate it
    with the transferred data.

Building access to Cloud Storage

  1. Navigate to the Google APIs Console in your web browser to access the
    Google project hosting the BigQuery and the Cloud Storage services you need
    to use.

  2. Click Google Cloud Storage > Interoperable Access to open its view.

  3. In the Component view of the Studio,
    paste Access key, Access secret from the Interoperable Access tab view to
    the corresponding fields, respectively.

  4. In the Bucket field, enter the path to
    the bucket you want to store the transferred data in. In this example, it is
    talend/documentation

    This bucket must exist in the directory in Cloud Storage

    use_case-tbigqueryoutput5.png
  5. In the File field, enter the directory
    where in Google Clould Storage you receive and create the file to be
    transferred to BigQuery. In this example, it is gs://talend/documentation/biquery_UScustomer.csv. The file
    name must be the same as the one you defined in the Local filename field.

    Note

    Troubleshooting: if you encounter issues such as Unable to read source URI of the file
    stored in Google Cloud Storage, check whether you put the same file name
    in these two fields.

  6. Enter 0 in the Header field to ignore no rows in the transferred
    data.

Getting Authorization code

  1. In the Run view of Talend Studio, click Run to execute this Job. The execution will pause at a given
    moment to print out in the console the URL address used to get the
    authorization code.

  2. Navigate to this address in your web browser and copy the authorization
    code displayed.

  3. In the Component view of tBigQueryOutput, paste the authorization code in
    the Authorization Code field.

Executing the Job

  • Press F6.

Once done, the Run view is opened automatically,
where you can check the execution result.

use_case-tbigqueryoutput-result.png

The data is transferred to Google BigQuery.

use_case-tbigqueryoutput-result2.png

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