Taskflows

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Parameters in taskflows

You can use a taskflow to pass input parameters and in-out parameters to a task.

You can design a

mapping

with input parameters or in-out parameters. When you add a

mapping

task to a taskflow, you can override the parameter values. The

mapping

task passes these parameters to the mapping. You can use the parameterized

mapping

task in different scenarios.

The following section explains input and in-out parameters and how you can use them in a taskflow:

Input parameters: An input parameter is a placeholder for a value or values in a
mapping
task. You define the value of the parameter when you configure the
mapping
task. For more information about input parameters, see
Mappings
and
Tasks
.

You can use a taskflow to override the following subset of
mapping
input parameters:

String. Changes the string value to be used as input for the
mapping
task.
Source object. Changes the object that the
mapping
task reads from.
Source connection. Changes the connection that the
mapping
task uses to read from the source.
Target connection. Changes the connection that the
mapping
task uses to write to the target.
Target object. Changes the object that the
mapping
task writes to.
Source_dataFormat. Changes the data format for a precision value or any other value for a particular column in the formatting file.
Source_defaultPrecision. Changes the precision value for all the columns in the formatting file.

For example, consider a fully parameterized
mapping
task. The
mapping
task uses an SQL connection to read from the
employeeaddress
table and a JDBC connection to write to the
employeedetails
table.

You can create a taskflow and override parameters in the
mapping
task. For example, you can use a Salesforce connection to read from the
employeeincome
table and a flat file connection to write to the file
income.txt
.

In-Out parameters: An in-out parameter is a placeholder for a value that can you can pass in to or out of a
mapping
task. Unlike input parameters, an in-out parameter can change each time a task runs. You can use a taskflow to override any type of in-out parameters that a
mapping
task supports. For more information about in-out parameters, see
Mappings
and
Tasks
.

For example, consider a
mapping
that keep tracks of how many rows it processes using an in-out parameter named
lastprocessedindex
. Every time you run the mapping, it resumes processing from this index. And also, let us say that every time the mapping is executed, it processes 5000 rows.

You can configure the taskflow such that the
mapping
task runs till it reaches records number, say, 50000.

If the in-out parameters in the selected mapping task are added or updated, you must reselect the mapping task in the taskflow to use the updated mapping task.