Variable Data Types - SSIS Expressions and Variables

Syntax

To declare a variable in SSIS, we use the "@" symbol followed by the variable name and the data type. For example, to declare a string variable named "name", we would write:

@name : string

Variables can be defined with various data types such as string, integer, float, boolean, object, etc.

SSIS expressions are used to manipulate the variables. Expressions use the same syntax as that of the VB (Visual Basic) language.

Example

@name : string
@age : int32
@pi : float
@is_valid : boolean

If @age > 18 && @is_valid == true
   @output = "The name is " + @name + ", age is " + CStr(@age) + " and pi is " + CStr(@pi)
Else
   @output = "Invalid input"

Explanation

In the above example, we have declared four different variables with their data types. We are then using an IF-ELSE loop to manipulate the variables using SSIS expressions. If the age is greater than 18 and the given inputs are valid, then the output will display the name, age and the value of pi as a concatenated string. If not, then it will return "Invalid input".

Use

Using variables and expressions in SSIS is helpful when we need to manipulate the flow of data and perform complex data transformations. We can define variables to hold values temporarily and manipulate it using expressions. This is useful when we need to perform calculations, conversions or when we need to store values temporarily so that we can use them later in the package.

Important Points

• SSIS expressions support VB syntax.
• We can declare and use different variable data types in SSIS.
• Variables and expressions are useful for performing complex data transformations.
• The values of variables can be modified during run time.

Summary

In SSIS, variables and expressions can be used to perform complex data transformations and manipulate the flow of data. The syntax for declaring variables is straightforward, and different data types can be used. Expressions use VB syntax and are helpful for performing calculations, conversions, and other data manipulations. Utilizing variables and expressions can save time and make our packages more dynamic and effective.