SqlDataReader [0] is empty

Question

I'm wanting to display the first row of a SqlDataReader (its the only row/column the database returns) in a text field. I thought this was the correct syntax but i get 'no data' error. I can ensure that the sql query being used should definitely return an answer, i've checked it in SQL Server.

SqlCommand sqlCommand = new SqlCommand(sqlQuery, sqlConnection);
sqlConnection.Open();
SqlDataReader reader = sqlCommand.ExecuteReader();
Label1.Text = reader[0].ToString();

reader[0] doesn't seem to show anything.

abatishchev · Accepted Answer · 2010-11-01 12:09:00Z

4

You need to actually read the data if I remember correctly using:

reader.Read()

Which you can iterate through or just use the first value.

edited Nov 1, 2010 at 12:09

abatishchev

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answered Nov 1, 2010 at 12:07

BenW

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Comments

Aliostad · Accepted Answer · 2010-11-01 12:07:30Z

2

You need to call read() to move to the rows. It is usually used as

   while(reader.read())
   {
        // do something
   }

In you case put reader.read() before assigning to label.

*Also remember always to close it - so use it in using block. *

answered Nov 1, 2010 at 12:07

Aliostad

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Comments

leppie · Accepted Answer · 2010-11-01 12:08:15Z

0

Please read the documentation for DataReader. The indexer provides a value based on the ordinal/column number. As you have not started (or are) moving through the reader, it will be empty.

answered Nov 1, 2010 at 12:08

leppie

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