SCRIPT TASK
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SCRIPT COMPONENT
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Control
Flow/Date Flow
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The
Script task is configured on the Control Flow tab of the designer and runs
outside the data flow of the package.
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The
Script component is configured on the Data Flow page of the designer and
represents a source, transformation, or destination in the Data Flow task.
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Purpose
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A
Script task can accomplish almost any general-purpose task.
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You
must specify whether you want to create a source, transformation, or
destination with the Script component.
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Raising
Results
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The
Script task uses both the TaskResult property and the optional ExecutionValue
property of the Dts object to notify the runtime of its results.
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The
Script component runs as a part of the Data Flow task and does not report
results using either of these properties.
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Raising
Events
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The
Script task uses the Events property of the Dts object to raise events. For
example: Dts.Events.FireError(0, "Event Snippet", ex.Message &
ControlChars.CrLf & ex.StackTrace
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The
Script component raises errors, warnings, and informational messages by using
the methods of the IDTSComponentMetaData100 interface returned by the
ComponentMetaData property. For example:
Dim myMetadata as
IDTSComponentMetaData100
myMetaData = Me.ComponentMetaData myMetaData.FireError(...) |
Execution
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A
Script task runs custom code at some point in the package workflow. Unless
you put it in a loop container or an event handler, it only runs once.
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A
Script component also runs once, but typically it runs its main processing
routine once for each row of data in the data flow.
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Editor
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The
Script Task Editor has three pages: General, Script, and Expressions. Only
the ReadOnlyVariables and ReadWriteVariables, and ScriptLanguage properties
directly affect the code that you can write.
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The
Script Transformation Editor has up to four pages: Input Columns, Inputs and
Outputs, Script, and Connection Managers. The metadata and properties that
you configure on each of these pages determines the members of the base
classes that are autogenerated for your use in coding.
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Interaction
with the Package
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In the
code written for a Script task, you use the Dts property to access other
features of the package. The Dts property is a member of the ScriptMain
class.
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In
Script component code, you use typed accessor properties to access certain
package features such as variables and connection managers. The PreExecute
method can access only read-only variables. The PostExecute method can access
both read-only and read/write variables.
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Using
Variables
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The
Script task uses the Variables property of the Dts object to access variables
that are available through the task’s ReadOnlyVariables and
ReadWriteVariables properties. For example: string myVar;
myVar = Dts.Variables["MyStringVariable"].Value.ToString();
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The
Script component uses typed accessor properties of the autogenerated based
class, created from the component’s ReadOnlyVariables and ReadWriteVariables
properties. For example:
string myVar; myVar = this.Variables.MyStringVariable;
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Using
Connections
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The
Script task uses the Connections property of the Dts object to access
connection managers defined in the package. For example:
string myFlatFileConnection;
myFlatFileConnection =
(Dts.Connections["Test Flat File
Connection"].AcquireConnection(Dts.Transaction) as String);
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The
Script component uses typed accessor properties of the autogenerated base
class, created from the list of connection managers entered by the user on
the Connection Managers page of the editor. For example:
IDTSConnectionManager100 connMgr;connMgr =
this.Connections.MyADONETConnection;
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LABEL: SSIS INTERVIEW QUESTIONS
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