Index was outside the bounds of the array exception

Question

Here is my code to get data from a flat file and insert into SQL Server. It is generating an exception (Index was outside the bounds of the array).

string path = string.Concat(Server.MapPath("~/TempFiles/"), Fileupload1.FileName);                       
string text = System.IO.File.ReadAllText(path);               
string[] lines = text.Split(' ');                                  
con.Open();                 
SqlCommand cmd = new SqlCommand();                 
string[] Values = new string[3];                                 
foreach (string line1 in lines)                 
{                     
    Values = line1.Split(';');                                           
    string query = "INSERT INTO demooo VALUES ('" + Values[0] + "','" + Values[1] + "','" + Values[2] + "')";                     
    cmd = new SqlCommand(query,con);                     
    cmd.ExecuteNonQuery();                  
} 

Answer 1

The exception happens because one of your lines has less than three elements separated with a semicolon. Even though you declare Values as a String array of three elements, affecting the variable to the result of String.Split() function makes that irrelevant: your array will have whatever length the returned array has. If it's less, your code will definitely fail.

If it's not supposed to happen I suggest you do an assertion in your code to help you debugging:

// ...
Values = line1.Split(';');
// the following will make the debugger stop execution if line.Length is smaller than 3
Debug.Assert(line1.Length >= 3);
// ...

As a side note, I should mention making a batch INSERT would be far more efficient. Also your way of declaring and reaffecting cmd variable isn't quite correct. And finally you should call String.Replace on your values to make sure any apostrophes is doubled. Otherwise your code will be open for SQL injection attacks.