Configuration - SQL Server Integration Services Design Patterns - page 402

ample, for setting property expressions). You'll make use of parameter values through
expressions or by reading them in a Script task. Parameter values are set before pack-
age execution begins, and their value cannot be changed while the package is running.
Parameters can be defined at the package level and at the project level. Package-
level parameters are visible only to tasks and components within that package—much
like package variables. Package parameters are defined in the $Package namespace.
Parameters defined at the project level are global—all packages within the project are
able to make use of them. Project parameters are defined in the $Project
namespace.
Figure 17-1 shows the new Parameters tab in SQL Server Data Tools for Business
Inteligence (SSDT-BI), which displays parameters defined at the package level. In ad-
dition to the standard properties you'd find on a package variable (such as Name ,
Type , and Value ), the Parameters tab expose three new properties: Description ,
Sensitive , and Required .
Figure 17-1 . Package-level parameters are created and displayed on their own tab in SSDT-BI
The Description field provides an easy way for the SSIS package developers
to document the arguments for their packages. It's recommended that you provide de-
scriptions for your parameters, especially in cases where the person running or config-
uring the packages is not the same person who developed them.
If a parameter is marked as Sensitive , its value will be stored in an encrypted
format within the package (or it will not be stored at all, depending on the package's
ProtectionLevel setting). Its value will also be masked when it is displayed in the
UI and will not be displayed in execution logs. Sensitive parameters can only be used
in expressions for properties that are marked as Sensitive (such as the Password
property of a connection manager). Sensitive parameter values can also be retrieved in
a Script task or script component with the Variable.GetSensitiveValue()
method.