tGreenplumRow Standard properties

Select the desired database type 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 drop-down list, select the desired 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, enter the password in double quotes in the pop-up dialog box, 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.

Specify additional JDBC parameters for the database connection created.

Select the desired database driver from the drop-down list, which can be Greenplum and PostgreSQL and defaults to Greenplum.

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

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 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.

tStatCatcher 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 more information about variables, see Using contexts and variables.

Usage rule

This component offers the flexibility 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 Dynamic schema and Creating a context group and define context variables in it.