sqlreader.GetValue(sqlreader.GetOrdinal(columnname) problem

[Guest]

Hi all,
I am stuck with this problem.
the code is like this:
Dim sqlreader As SqlDataReader =
myCommand.ExecuteReader(CommandBehavior.CloseConnection)

sqlreader.GetValue(sqlreader.GetOrdinal(columnname) give me the following in
the watch window:

sqlreader.GetValue(sqlreader.GetOrdinal("enrolldate")) Run-time exception
thrown : System.InvalidOperationException - Invalid attempt to read when no
data is present.
But I can get the column number: sqlreader.GetOrdinal("enrolldate") is 1.
What's going on?
Thank you.
Betty

 

[Brian]

Do you call sqlreader.Read() before trying to get a value? No rows are
fetched until you do this.

 

[Guest]

When I look at the sqlreader in the watch window, it gave the following info:

Depth 0 Integer
FieldCount 62 Integer
HasRows True Boolean
IsClosed False Boolean
Item <cannot view indexed property> Object
RecordsAffected -1 Integer

So that means I pull the data through the procedure, right.

 

[Guest]

Enclose your code in a while loop like this:

While sqlreader.Read()
'place the code to GetValue here
End While

 

[sloan]

As other people has previous posted:
http://www.lhotka.net/cslacvs/viewcvs.cgi/*checkout*/CSLA10/CSLA/SafeDataReader.vb

this SafeDataReader has these built in checks for you.

But... yes, you have to call the Read() method ... and put your code in the
Read() loop ....

Its kinda like "If not rs.EOF".. but its not quite that exactly either.

...

The SafeDataReader is a nice bit of code to make the IDataReader a little
easier to deal with.

 

[Guest]

thank you all. I missed that part .
--
Betty

As other people has previous posted:
http://www.lhotka.net/cslacvs/viewcvs.cgi/*checkout*/CSLA10/CSLA/SafeDataReader.vb

this SafeDataReader has these built in checks for you.

But... yes, you have to call the Read() method ... and put your code in the
Read() loop ....

Its kinda like "If not rs.EOF".. but its not quite that exactly either.

...

The SafeDataReader is a nice bit of code to make the IDataReader a little
easier to deal with.