Select a type of database from the list and click
Apply.

Property type

Either Built-in or
Repository.

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.

Host

Database server IP address

Port

Listening port number of DB server.

Database

Name of the database

Schema

Exact name of the schema.

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
(columns) to be processed and passed on to the next component. When you create a Spark
Job, avoid the reserved word line when naming the
fields.

Built-In: You create and store the schema locally for this component
only.

Repository: You have already created the schema and stored it in the
Repository. You can reuse it in various projects and Job designs.

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

Name of the table to be read.

Query type

Either Built-in or
Repository
.

Built-in: Fill in manually the
query statement or build it graphically using SQLBuilder.

Repository: Select the relevant
query stored in the Repository. The Query field gets accordingly filled in.

Guess Query

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

Query

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

Die on error

This check box is selected by default. Clear the check box to skip
the row on error and complete the process for error-free rows. If
needed, you can retrieve the rows on error via a Row > Rejects link.

Additional JDBC Parameters

Specify additional JDBC parameters for the
database connection created.

This property is not available when the Use an existing connection
check box in the Basic settings view is selected.

Propagate QUERY’s recordset

Select this check box to insert the result of the query into a
COLUMN of the current flow. Select this column from the use column list.

Use PreparedStatement

Select this check box if you want to query the database using a
PreparedStatement. In the Set
PreparedStatement Parameter table, define the
parameters represented by “?” in the SQL instruction of the
Query field in the Basic Settings tab.

Parameter Index: Enter the
parameter position in the SQL instruction.

Parameter Type: Enter the parameter
type.

Parameter Value: Enter the
parameter value.

Commit every

Number of rows to be completed before committing batches of rows
together into the DB. This option ensures transaction quality (but
not rollback) and above all better performance on executions.

tStat
Catcher Statistics

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

Global Variables 

QUERY: the 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 rule

This component offers the flexibility benefit of the DB query and
covers all possible SQL queries.

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 Reading data from databases through context-based dynamic connections and 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.

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. You can find more details about how to install external modules in
Talend Help Center (https://help.talend.com).