.net SqlDataReader VB C#

Question

I have this statement:

if (sqlClass.Reader != null && sqlClass.Reader.HasRows)
    {
        do
        {
            data = sqlClass.Reader.GetString(0); //error line System.InvalidOperationException {"Invalid attempt to read when no data is present."}
        } while (sqlClass.Reader.Read());
    }

the object sqlClass.Reader is of type System.Data.SqlClient.SqlDataReader

In C# it gives me an InvalidOperationException but in VB it worked fine, what would the reason be and how do I solve this?

show the entire error and the line of error too.

Ahmed ilyas
– Ahmed ilyas

2014-05-23 10:21:07 +00:00
Commented May 23, 2014 at 10:21 — Ahmed ilyas
– Ahmed ilyas, Commented May 23, 2014 at 10:21

Dmitrii Bychenko · Accepted Answer · 2014-05-23 10:28:26Z

4

Something like this:

if (null != sqlClass.Reader)
{
    while (sqlClass.Reader.Read())
    {
        data = sqlClass.Reader.GetString(0);
    }
}

edited May 23, 2014 at 10:28

Dmitrii Bychenko

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answered May 23, 2014 at 10:23

Donal

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4 Comments

Ahmed ilyas Over a year ago

damn you beat me to it. I was going to write just that. its a matter of using a different type of while loop as you demonstrated

Dmitrii Bychenko Over a year ago

You'd rather had preserved qlClass.Reader != null

Dmitrii Bychenko Over a year ago

sqlClass.Reader.HasRows if of no use here

Donal Over a year ago

HasRows checks if the reader has retrieved data. The null check will just check if the object is not null.

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