tAmazonAuroraInput - 6.1

Talend Components Reference Guide

EnrichVersion
6.1
EnrichProdName
Talend Big Data
Talend Big Data Platform
Talend Data Fabric
Talend Data Integration
Talend Data Management Platform
Talend Data Services Platform
Talend ESB
Talend MDM Platform
Talend Open Studio for Big Data
Talend Open Studio for Data Integration
Talend Open Studio for Data Quality
Talend Open Studio for ESB
Talend Open Studio for MDM
Talend Real-Time Big Data Platform
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Function

This component reads an Amazon Aurora database and extracts fields based on a query.

Purpose

This component executes a database query with a strictly defined order which must correspond to the schema definition. Then it passes on the field list to the next component via a Row > Main link.

tAmazonAuroraInput properties

Component family

Cloud/AmazonRDS/Aurora

Basic settings

Property Type

Either Built-In or Repository.

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

 

 

Built-In: No property data stored centrally.

 

 

Repository: Select the repository file in which the properties are stored. The database connection fields that follow are completed automatically using the data retrieved.

 

Use an existing connection

Select this check box and in the Component List click the relevant connection component to reuse the connection details you already defined.

Note

When a Job contains the parent Job and the child Job, if you need to share an existing connection between the two levels, for example, to share the connection created by the parent Job with the child Job, you have to:

  1. In the parent level, register the database connection to be shared in the Basic settings view of the connection component which creates that very database connection.

  2. In the child level, use a dedicated connection component to read that registered database connection.

For an example about how to share a database connection across Job levels, see Talend Studio User Guide.

 

Host

Type in the IP address or hostname of the Amazon Aurora database.

 

Port

Type in the listening port number of the Amazon Aurora database.

 

Database

Type in the name of the database you want to use.

 

Username and Password

Type in the database user authentication data.

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

 

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.

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

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 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.

 

 

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.

 

Table Name

Type in the name of the table to be read.

 

Query Type and Query

Enter the database query paying particularly attention to the proper sequence of the fields in order to match the schema definition.

Warning

If using the dynamic schema feature, the SELECT query must include the * wildcard, to retrieve all of the columns from the table selected.

 

Guess Query

Click the button to generate the query which corresponds to the table schema in the Query field.

 

Guess schema

Click the button to retrieve the schema from the table.

 

Specify a data source alias

Select this check box and specify the alias of a data source created on the Talend Runtime side to use the shared connection pool defined in the data source configuration. This option works only when you deploy and run your Job in Talend Runtime.

This check box disappears when the Use an existing connection check box is selected.

 

Data source alias

Type in the alias of the data source created on the Talend Runtime side.

This field appears only when the Specify a data source alias check box is selected.

Advanced settings

Additional JDBC parameters

Specify additional connection properties for the database connection you are creating. When you need to handle data of the time-stamp type 0000-00-00 00:00:00 using this component, set the parameter to noDatetimeStringSync=true&zeroDa√ā¬≠teTimeBehavior=convertToNull.

This field disappears when the Use an existing connection check box in the Basic settings view is selected.

 

Enable stream

Select this check box to enable streaming over buffering which allows the code to read from a large table without consuming a large amount of memory in order to optimize the performance.

 

Trim all the String/Char columns

Select this check box to remove leading and trailing whitespace from all the String/Char columns.

 

Trim column

Select the check box(es) in the Trim column to remove leading and trailing whitespace from the corresponding column(s).

This option disappears when the Trim all the String/Char columns check box is selected.

 

tStatCatcher Statistics

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

Dynamic settings

Click the [+] button to add a row in the table and fill the Code field with a context variable to choose your database connection dynamically from multiple connections planned in your Job. This feature is useful when you need to access database tables having the same data structure but in different databases, especially when you are working in an environment where you cannot change your Job settings, for example, when your Job has to be deployed and executed independent of Talend Studio.

The Dynamic settings table is available only when the Use an existing connection check box is selected in the Basic settings view. Once a dynamic parameter is defined, the Component List box in the Basic settings view becomes unusable.

For examples on using dynamic parameters, see Scenario 3: Reading data from MySQL databases through context-based dynamic connections and Scenario: Reading data from different MySQL databases using dynamically loaded connection parameters. For more information on Dynamic settings and context variables, see Talend Studio User Guide.

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.

QUERY: the SQL query statement being processed. This is a Flow variable and it returns a string.

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 usually used as a start component of a Job or Subjob and it needs an output link.

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.

Scenario: Handling data with Amazon Aurora

This scenario describes a Job that writes the user information into Amazon Aurora, and then reads the information in Amazon Aurora and displays it on the console.

The scenario requires the following seven components:

  • tAmazonAuroraConnection: opens a connection to Amazon Aurora.

  • tFixedFlowInput: defines the user information data structure, and sends the data to the next component.

  • tAmazonAuroraOutput: writes the data it receives from the preceding component into Amazon Aurora.

  • tAmazonAuroraCommit: commits in one go the data processed to Amazon Aurora.

  • tAmazonAuroraInput: reads the data from Amazon Aurora.

  • tLogRow: displays the data it receives from the preceding component on the console.

  • tAmazonAuroraClose: closes the connection to Amazon Aurora.

Adding and linking the components

  1. Create a new Job and add seven components listed previously by typing their names in the design workspace or dropping them from the Palette.

  2. Connect tFixedFlowInput to tAmazonAuroraOutput using a Row > Main connection.

  3. Do the same to connect tAmazonAuroraInput to tLogRow.

  4. Connect tAmazonAuroraConnection to tFixedFlowInput using a Trigger > OnSubjobOk connection.

  5. Do the same to connect tFixedFlowInput to tAmazonAuroraCommit, tAmazonAuroraCommit to tAmazonAuroraInput, and tAmazonAuroraInput to tAmazonAuroraClose.

Configuring the components

Opening a connection to Amazon Aurora

  1. Double-click tAmazonAuroraConnection to open its Basic settings view.

  2. In the Host, Port, Database, Username and Password fields, enter the information required for the connection to Amazon Aurora.

Writing the data into Amazon Aurora

  1. Double-click tFixedFlowInput to open its Basic settings view.

  2. Click the [...] button next to Edit schema and in the pop-up window define the schema by adding three columns: id of Integer type, and name and city of String type.

    Click OK to validate the changes and accept the propagation prompted by the pop-up dialog box.

  3. In the Mode area, select Use Inline Content (delimited file) and enter the following user information in the Content field.

    1;George;Bismarck
    2;Abraham;Boise
    3;Taylor;Nashville
    4;William;Jefferson City
    5;Alexander;Jackson
    6;James;Boise
    7;Gerald;Little Rock
    8;Tony;Richmond
    9;Thomas;Springfield
    10;Andre;Nashville
  4. Double-click tAmazonAuroraOutput to open its Basic settings view.

  5. Select the Use an existing connection check box and in the Component List that appears, select the connection component you have configured.

  6. In the Table field, enter or browse to the table into which you want to write the data. In this example, it is TalendUser.

  7. Select Drop table if exists and create from the Action on table drop-down list, and select Insert from the Action on data drop-down list.

  8. Double-click tAmazonAuroraCommit to open its Basic settings view.

  9. Clear the Close Connection check box if it is selected.

Retrieving the data from Amazon Aurora

  1. Double-click tAmazonAuroraInput to open its Basic settings view.

  2. Select the Use an existing connection check box and in the Component List that appears, select the connection component you have configured.

  3. Click the [...] button next to Edit schema and in the pop-up window define the schema by adding three columns: id of Integer type, and name and city of String type. The data structure is same as the structure you have defined for tFixedFlowInput.

  4. In the Table Name field, enter or browse to the table into which you write the data. In this example, it is TalendUser.

  5. Click the Guess Query button to generate the query. The Query field will be filled with the automatically generated query.

  6. Double-click tLogRow to open its Basic settings view.

  7. In the Mode area, select Table (print values in cells of a table) for better readability of the result.

Closing the connection to Amazon Aurora

  1. Double-click tAmazonAuroraClose to open its Basic settings view.

  2. In the Component List, select the connection component you have configured.

Saving and executing the Job

  1. Press Ctrl + S to save the Job.

  2. Press F6 or click Run on the Run tab to run the Job.

    As shown above, the user information is written into Amazon Aurora, and then the data is retrieved from Amazon Aurora and displayed on the console.