SSIS Parameters And Variables
This is another of those, get my head clear, overview posts. There’s really nothing here that probably isn’t clear with a bit of study. The only hang up I had, and really why I wrote this, is that values that can be assigned to a parameter came up in the practice test.
Parameters
Can be assigned at either the project or package level. They are used to assign values at run-time. They can also be used in scripts and precedence constraints.
There are 3 types of values that can be assigned to a parameter:
- Execution Value: Is assigned to a specific instance of an execution value. It only applies to that specific execution. It overrides all other values.
- Server Value: This is the value assigned within the scope of the project. It overrides the design value.
- Design Value: This is the value assigned when the project is created.
A single parameter can assign values to multiple package properties.
Variables
Variables store values that a package, container, task or event handler can use at run time. They can also be used in scripts and precedence constraints.
There are two-types of variables:
- System: Defined by integration services.
- User: Defined by developers.
Variables are used in other ways as well.
- Set package properties at run time.
- To store data values. As an example, a Execute SQL Task can store its results in a variable.
- As a condition in a package.
- As a condition in a container, for instance, a For Loop task.
- As an expression.
And, from the 10,000 foot level, that’s pretty much that.