Pass a variable using Script task in SSIS

To use a variable in a script, first ensure that the variable has been added to either the list contained in the ReadOnlyVariables property or the list contained in the ReadWriteVariables property of this script task, according to whether or not your code needs to write to the variable.

//Example of reading from a variable:
DateTime startTime = (DateTime) Dts.Variables["System::StartTime"].Value;

//Example of writing to a variable:
Dts.Variables["User::myStringVariable"].Value = "new value";

//Example of reading from a package parameter:
int batchId = (int) Dts.Variables["$Package::batchId"].Value;

//Example of reading from a project parameter:
int batchId = (int) Dts.Variables["$Project::batchId"].Value;

//Example of reading from a sensitive project parameter:
int batchId = (int) Dts.Variables["$Project::batchId"].GetSensitiveValue();

I do it like this:

When opening the script task properties you have two fields, ReadOnlyVariables and ReadWriteVariables. Write your variable name into the according field based on your needs, in your case User::Variable.

In the code you can use it like this

Dts.Variables["User::Variable"].Value.ToString()

Following code in the Script task may help you

var dbServerName = Dts.Variables["yourVariableName"].Value.ToString();

var sqlConnString = string.Format("Server=ServerName;Integrated Security=true;user=;pwd=;database={0}", dbServerName);

SqlConnection sqlConn = new SqlConnection(sqlConnString);