Using Property Expressions to Specify Property Values for Data Flow Objects

Mis à jour : 5 décembre 2005

The values of certain properties of data flow objects can be specified by using property expressions available on the Data Flow task container.

For information about using property expressions, see Utilisation des expressions de propriété dans des packages.

You can use property expressions to customize configurations for each deployed instance of a package. You can also use property expressions to specify run-time constraints for a package by using the /set option with the dtexec command prompt utility. For example, you can constrain the MaximumThreads used by the Sort transformation, or the MaxMemoryUsage of the Fuzzy Grouping and Fuzzy Lookup transformations. If unconstrained, these transformations may cache large amounts of data in memory.

Creating Expressions for Properties of Data Flow Objects

To specify a property expression for one of the properties of data flow objects listed in this topic, display the Properties window for the Data Flow task by selecting the Data Flow task on the Control Flow surface of the designer, or by selecting the Data Flow tab of the designer without selecting any individual component or path. Select the Expressions property and click the ellipsis (...) to display the Property Expressions Editor dialog box. Drop down the Property list to select a property, then type an expression in the Expression text box, or click the ellipsis (...) to display the Expression Builder dialog box.

The Property list displays available properties for only those data flow objects that you have already placed on the Data Flow surface of the designer. Therefore, you cannot use the Property list to view all the possible properties of data flow objects that support property expressions. For example, if you have placed a DataReader Source on the designer surface, the Property list contains an entry for the [DataReader Source].[SqlCommand] property. The list also displays many properties of the Data Flow task itself.

Properties of Data Flow Objects That Support Property Expressions

The values of the properties in the following list can be specified by using property expressions.

Data Flow Sources

Data Flow Transformations

Data Flow Destinations

Change History

Voir aussi

Référence

Common Properties
Source Custom Properties
Transformation Custom Properties
Destination Custom Properties
Path Properties

Autres ressources

Utilisation des expressions de propriété dans des packages

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