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.

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.

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.

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

Displays each row of the output flow as a key-value list.

With this mode selected, you can choose to show either the unique name
or the label of component, or both of them, for each output row.

Separator

(For Basic mode only)

Enter the separator which will delimit data on the Log display.

Print header

(For Basic mode only)

Print component unique name in front of each
output row

(For Basic mode only)

Select this check box to show the unique name the component in front
of each output row to differentiate outputs in case several tLogRow components are used.

Print schema column name in front of each
value

(For Basic mode only)

Select this check box to retrieve column labels from output
schema.

Use fixed length for values

(For Basic mode only)

Select this check box to set a fixed width for the value
display.

Print content with log4j

Select this check box to output the data flow content if the log4j
feature is activated and the log4j output level is set to INFO or lower
than INFO for your Job. For how to activate the log4j feature and
customize the log4j output level, refer to
Talend Studio

User
Guide.

Global Variables

NB_LINE: the number of rows processed. This is an After
variable and it returns an integer.

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 can be used as intermediate step in a data flow or as a
n end object in the Job flowchart.