tJavaDBInput – Docs for ESB 5.x

Component family

Databases/JavaDB

Function

tJavaDBInput reads a database and
extracts fields based on a query.

Purpose

tJavaDBInput executes a DB 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 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.

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.

Framework

Select your Java database framework on the list

Database

Name of the database

DB root path

Browse to your database root.

Username and
Password

DB 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 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:

Query type and Query

Enter your DB query paying particularly attention to properly
sequence the fields in order to match the schema definition.

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.

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 covers all possible SQL database queries.

Log4j

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.

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.