SSIS Null handling, script task

Question

I am having trouble with MS SSIS. I would like to download and upload stuff to database. I am looking for the best practice, or why i get an error.

I use the control flow (other tasks are called). There are nulls in a column in the data I download. For this I can't use string or integer, or else it exits with error (execute sql task). So I use object. Example: Variable sBorderName is object, the data from a column goes here.

I would like to upload this to an other database table. There can also be null in that colum for example. I cannot upload the object variable, because I get database type missmatch.

When I try to eliminate the null-s with a script task (C#), I use the following: sBorderName is object sBorderNameSafe is string

if (Dts.Variables["User::sBorderName"].Value == null)
{
    Dts.Variables["User::sBorderNameSafe"].Value = "NULL ERROR";
}
else
{
    Dts.Variables["User::sBorderNameSafe"].Value = 
        (String)Dts.Variables["User::sBorderName"].Value;
}

I get runtime error, with no hint on what is wrong. The error originates from the else case. I have double checked the variables, scope, write/read permissions etc.

Can you please help me? What is wrong with this? What is the way to solve the problem if you have a better idea?

Sziro

UPDATE:

Dts.Events.FireWarning(14, "Display Script", "sBorderName is:" + Dts.Variables["User::sBorderName"].Value, "", 0); 

does work, it shows "sBorderName is: "

However every casting of the value exits with runtime error

(String)Dts.Variables["User::sBorderName"].Value

How can one handle this correctly?

Answer 1

Convert.ToString(Dts.Variables("sBorderName ").Value)

如果变量有时可以为null，那就可以了。