System and User-Defined Variables - ( SSIS Expressions and Variables )
Syntax
Variables can be created and used in SSIS packages using the following syntax:
@[User::VariableName]
Example
@[User::CurrentYear]
Output
The output will be the value assigned to the variable CurrentYear
.
Explanation
Variables are used to store values that can be used throughout the SSIS package. These values can be system-defined or user-defined. System-defined variables are created automatically by SSIS and cannot be changed. User-defined variables, on the other hand, are created by the user and can be used to store any value needed for the package.
These variables can be used in expressions, scripts, and other parts of the package, making it easy to modify the behaviour of the package without having to modify the underlying code.
Use
Variables can be used in various ways in SSIS packages, such as:
- Controlling the flow of the package
- Providing values needed for the package
- Modifying package properties
- Storing results of calculations or transformations
Important Points
- Variables can be set using expressions or a script task.
- Variables can be used to store values of any data type.
- Variables can be scoped at different levels, such as at the package, task, or container level.
- Variables can be accessed across different parts of the package, but are only available during the package execution.
Summary
In summary, variables are an important part of SSIS packages, allowing users to store and manipulate values needed for the package. System-defined variables are created automatically by SSIS, while user-defined variables are created by the user. These variables can be used in expressions, scripts, and other parts of the package, making it easy to modify the behaviour of the package without having to modify the underlying code.