tSQLiteInput - 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
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Talend ESB
Talend MDM Platform
Talend Open Studio for Big Data
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Talend Open Studio for Data Quality
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Talend Real-Time Big Data Platform
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

tSQLiteInput Properties

Component family

Databases

 

Function

tSQLiteInput reads a database file and extracts fields based on an SQL query. As it embeds the SQLite engine, no need of connecting to any database server.

Purpose

tSQLiteInput executes a DB query with a defined command which must correspond to the schema definition. Then it passes on rows to the next component via a Main row link.

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 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.

 

Click this icon to open a database connection wizard and store the database connection parameters you set in the component Basic settings view.

For more information about setting up and storing database connection parameters, see Talend Studio User Guide.

 

Database

Filepath to the SQLite database file.

 

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: The schema is 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. 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.

 

Query 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.

 

Query

If your query is not stored in the Repository, type in your DB query paying particularly attention to properly sequence 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.

Advanced settings

Trim all the String/Char columns

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

 

Trim column

Remove leading and trailing whitespace from defined columns.

 

tStatCatcher Statistics

Select this check box to collect log data at the 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 processed. 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 standalone as it includes the SQLite engine. This is a startable component that can iniate a data flow processing.

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: Filtering SQlite data

This scenario describes a rather simple job which uses a select statement based on a filter to extract rows from a source SQLite Database and feed an output SQLite table.

  • Drop from the Palette, a tSQLiteInput and a tSQLiteOutput component from the Palette to the design workspace.

  • Connect the input to the output using a row main link.

  • On the tSQLiteInput Basic settings, type in or browse to the SQLite Database input file.

  • The file contains hundreds of lines and includes an ip column which the select statement will based on

  • On the tSQLite Basic settings, edit the schema for it to match the table structure.

  • In the Query field, type in your select statement based on the ip column.

  • On the tSQLiteOutput component Basic settings panel, select the Database filepath.

  • Type in the Table to be fed with the selected data.

  • Select the Action on table and Action on Data. In this use case, the action on table is Drop and create and the action on data is Insert.

  • The schema should be synchronized with the input schema.

  • Save the job and run it.

The data queried is returned in the defined SQLite file.

For an example of how to use dynamic schemas with Input components, see Scenario 4: Writing dynamic columns from a MySQL database to an output file.