datareader

In my db table Layout, there's one column whose type is hierarchyid (column index=4). When trying to set-up new environment (a virtual web-server, created from XEN server), then running the site, I've met with this issue: Exception message: DataReader.GetFieldType(4) returned null. Exception data: System.Collections.ListDictionaryInternal I've made some search and found out there are already some topic on it (such as on MSDN ). But even when I added the C:\Program Files\Microsoft SQL Server\100\SDK\Assemblies\Microsoft.SqlServer.Types.dll library, it seems like db type in structure

How to handle multiple ResultSets, each with multiple Rows? The call to NextResult() breaks the while loop. Some of my SPs return multiple ResultSets. I'm handling these with NextResult() but when I do and my SP only has a single ResultSet, I see the while loop with Read() finishes leaving me with only the first Row. Without the call to NextResult() I get all the rows for the first ResultSet but of course the second and subsequent ResultSets don't get processed? using (IDataReader reader = storedProcedure.ExecuteReader( CommandBehavior.CloseConnection, parameterNames as string[], arguments)) {

The error above occurs when I try to do a dataReader.Read on the data recieved from the database. I know there are two rows in there so it isnt because no data actually exists. Could it be the CommandBehavior.CloseConnection, causing the problem? I was told you had to do this right after a ExecuteReader? Is this correct? try { _connection.Open(); using (_connection) { SqlCommand command = new SqlCommand("SELECT * FROM Structure", _connection); SqlDataReader dataReader = command.ExecuteReader(CommandBehavior.CloseConnection); if (dataReader == null) return null; var newData = new List<Structure

Microsoft (and many developers) claim that the SqlDataReader.GetOrdinal method improves the performance of retrieving values from a DataReader versus using named lookups ie. reader["ColumnName"]. The question is what is the true performance difference if dealing with small, paged record sets? Is it worth the extra overhead of finding and referencing ordinal indexes throughout the code? Microsoft recommends not calling GetOrdinal within a loop. That would include indirect calls with the string indexer. You can use GetOrdinal at the top of your loop put the ordinals in an array and have the

I read a string using this format with a data reader. How can I read in a date using similar format? while (MyReader.Read()) { TextBox1.Text = (string)MyReader["Note"]; } Sukhjeevan Try as given below: while (MyReader.Read()) { TextBox1.Text = Convert.ToDateTime(MyReader["DateField"]).ToString("dd/MM/yyyy"); } in ToString() method you can change data format as per your requirement. If the query's column has an appropriate type then var dateString = MyReader.GetDateTime(MyReader.GetOrdinal("column")).ToString(myDateFormat) If the query's column is actually a string then see other answers.

Similar to this question , but the answers never really got around to what I want to know. Is there any standards around getting values from a DataReader? I.e., is this dataReader.GetString(dataReader.GetOrdinal("ColumnName")); considered better/worse/the same as this? (string) dataReader["ColumnName"]; Here is the way that I do it: Int32 ordinal = dataReader.GetOrdinal("ColumnName"); if (!dataReader.IsDBNull(ordinal)) yourString = dataReader.GetString(ordinal); It is important to check for DBNull like I have shown above because if the field is null in the DataReader it will throw an exception