The Expression component allows you to write simple expressions and assignments without having to resort to Visual Studio for Applications, which whilst undoubtedly powerful and flexible can be difficult to work with and frustrating to use for simple scenarios. VSTA also tends to make integration packages more opaque.
This component can be used on both the control and data flow surfaces, and is designed for simple scenarios such as data conversion, incrementing a variable or assigning a value. The full .Net Framework is available, and the syntax is loosely that of C# (though a trailing semicolon is optional). Javascript style
alert and
confirm functions are also available.
On double clicking the component, the following configuration page is displayed :
You simple specify an expression, which can contain [Column] and @Variable tokens (use the Insert Token link for help in inserting these), and a variable or column to assign the result to. You can also use system variable tokens.
You don't have to store the result, if for example you just want to execute an
alert or
confirm statement.
All BlueSSIS data-flow components support properties 'Fail on truncation' and 'Unicode mode', allowing you to define applicable truncation and Unicode settings. These properties can be found in the Visual Studio/BIDS Properties window as shown below :
