let’s take a look at the simple definition of variables in SSIS
Variables store values which can be used to update tasks in control flow , data flow and in event handlers, dynamically during the run time of the package
Types of Variables
1) System variables (system defined)
2) User defined Variables
How they are accessed(scope) : system variables can be accessed from any task(if it allows) in the package and these can only be read
User Defined Variables : are created by the users and data types include string, int16, int32, int64, double, dbnull, object, single, Boolean, char, Uint32, Uint64, datetime, sbyte
how they accessed in the package is kind of different from system defined variables and now we can start using the word called scope
if a variable is created in data flow (scope) it can not be accessed from control flow
so lets consider different scopes here
Package level : a variable created with out highlighting any of the task in control flow
Task level : a variable created with highlighting any of the tasks in control flow
Data flow : variable created in data flow by selecting or not selecting any tasks are transformations in data flow
Important : variables are case sensitive
a variable as Var1 is not same as var1