Out of range error on SqlDataReader

问题

I'm using a SqlDataReader and get this exception when trying to read a column...

System.IndexOutOfRangeException: record

Here is the code...

SqlCommand select = new SqlCommand("SELECT RTRIM(LTRIM(PART_NO)) AS PART_NO, record AS CUSTOMER_NO FROM [RMAData].[dbo].[IMPORTING_ORDER_EDI] WHERE sessionID = '" + Session.SessionID + "'", connection);
SqlDataReader reader = select.ExecuteReader();

if (reader.HasRows)
{
   while (reader.Read())
   {
       lblWebMasterMessage.Text += "record " + reader["record"].ToString() + "<br />";
...

If I change the lblWebMasterMessage.Text to the following it works just fine...

lblWebMasterMessage.Text += "record " + reader["PART_NO"].ToString() + "<br />";

The difference between record and PART_NO in the SQL Server table is that 'record' is a primary key and an int, PART_NO is a varchar(100).

The trouble is, I need the 'record' to identify the record to update it later...

I really can't see why it can return one field and not the other?

回答1:

That's because you have no field named "record", you aliased it to "CUSTOMER_NO" so change the code to:

lblWebMasterMessage.Text += "record " + reader["CUSTOMER_NO"].ToString() + "<br />";

That said, you can also use index instead of name so to read the second column:

lblWebMasterMessage.Text += "record " + reader[1] + "<br />";

回答2:

In my case this error was because I was accidentally executing two select statements in my command text. I had two separate output results and the first output didn't contain the column name I was reading and hence the error.

来源：https://stackoverflow.com/questions/15005479/out-of-range-error-on-sqldatareader

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ASP.NET

sqldatareader