Question

I have a standalone application that does data checking of flat files before they are imported into a SQL database.

In a context like this, does it make sense to throw a System.Data.ConstraintException? (The example is contrived.)

if(_keys.ContainsKey(key))
{
    throw new ConstraintException(string.Format("Uniqueness violated! " + 
        "This unique combination of '{0}' already found on line {1}", 
        GetUniquenessColumnList(), _keys[key] ));
}

ConstraintException’s documentation states that it “represents the exception that is thrown when attempting an action that violates a constraint.”

Is there a problem with using the built-in exception this way? Is there a better one to use? Should I build my own, even though this exception seems tailor-made to my situation?

Answer 1

I think you’ve answered your own question

…this exception seems tailor-made to my situation?

Why reinvent the wheel?

EDIT:

Check out this MSDN article: Choosing the Right Type of Exception to Throw

Consider throwing existing exceptions residing in the System
namespaces instead of creating custom exception types.

…

Do not create and throw new exceptions just to have your team’s exception.