sql中的“未指定错误”几秒钟后消失

Question

I built a parser that takes data stored in an xml file and sends it into a Microsoft Access database using linq-to-sql. I have the sql insert commands and they work... until they don't.

It's odd, I have each SQL command run (I keep them in a List and execute each command one at a time) and the first 40 or so run fine until they start hitting "unspecified error"s. The thing is, if I swallow the exception and instead have the exception catcher keep retrying, after a few seconds, they start working again. This means it's not an error of the SQL query itself (or at least how it's written).

This pattern repeats (there are thousands of inserts) many times. If I do normal exception handling, the program will just skip a few records while the error happens and keep inserting when whatever causes it temporarily goes away. if I let it run it's course, it inserts some records, skips some, inserts, skips, repeat and eventually inserts less than 2/3 of the records.

Is there any reason why my computer would only run 40 or so Inserts and then refuse to run more for a random but short interval?

I'm at a loss on what could be causing this.

The application is natively run; it does not use any server/web communication and all I found when looking for "unspecified error" pointed me to occurrences in ADO.NET applications.

Here's the code the error happens in:

public static string insertQuery(string sql)
    {
        string connetionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Documents and Settings\Owner\Desktop\Arbeit\TrademarkParserproject1\TrademarkParserproject\bin\x86\Debug\Database.accdb";
        OleDbConnection connection;
        OleDbDataAdapter oledbAdapter = new OleDbDataAdapter();
        connection = new OleDbConnection(connetionString);

        string success = "false";

        try
        {
            connection.Open();
            oledbAdapter.InsertCommand = new OleDbCommand(sql, connection);
            oledbAdapter.InsertCommand.ExecuteNonQuery();

        }

        catch (Exception ex)
        {
            success = ex.ToString();
            return success;
        }

        success = "true";
        return success;
    }

Note, I have the application running in X86 mode to avoid errors with the ACE.OLEDB.12.0 adapter.

Answer 1

One thing that stands out, is you never close/dispose your SqlConnection. OleDbDataAdapter is also disposable and should be disposed. A 'using' statement is a convenient construct here:

public static string insertQuery(string sql)
{
    string connetionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Documents and Settings\Owner\Desktop\Arbeit\TrademarkParserproject1\TrademarkParserproject\bin\x86\Debug\Database.accdb";
    using(var oledbAdapter = new OleDbDataAdapter())
    using(var connection = new OleDbConnection(connetionString))
    {
        string success = "false";

        try
        {
            connection.Open();
            oledbAdapter.InsertCommand = new OleDbCommand(sql, connection);
            oledbAdapter.InsertCommand.ExecuteNonQuery();
        }

        catch (Exception ex)
        {
            success = ex.ToString();
            return success;
        }

        success = "true";
        return success;
    }
}