Getting a statabase query returned as string in c#

I am working with a dbf database. I need to query it to get information back in string format. The dbf file is set up as follows:

Student Name  Student Number  Student Description
HelloWorld      123456789          Present
WorldHello      987654321          Absent

Here is the code i have so far:

    OleDbCommand command;
    OleDbConne开发者_运维知识库ction conn = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0; Data Source = " + dbfPath + ";Extended Properties=dBase III");
    command = new OleDbCommand("SELECT STUDENTNAME, STUDENTNUMBER, STUDENTDESCRIPTION" + " FROM " + DbfFile + " WHERE " + STUDENTNAME='HelloWorld', conn);

Now i want to get the result as a comma seperated string as follows:

HelloWorld,123456789,Present

How can i do this?

---

There is 2 options.. 1 - Create a DataReader

 myCommand.ExecuteReader ( CommandBehavior.CloseConnection );
   string result;
   while ( myReader.Read ( ) ) {
      result = string.format("{0},{1},{2}"),myReader.GetString(0),myReader.GetString(1),myReader.GetString(2) );
   }
   myReader.Close ( );
   myConn.Close ( );

2 - Modify the SQL Statement

command = new OleDbCommand("SELECT STUDENTNAME + ',' STUDENTNUMBER + ',' + STUDENTDESCRIPTION" + " FROM " + DbfFile + " WHERE " + STUDENTNAME='HelloWorld', conn);
string result = (string)command.ExecuteScalar();

---

Fetch the results using a DataReader (as explained here), and concatenate the results:

using (var reader = command.ExecuteReader())
{
    while (reader.Read())
    {
        string line = string.Format(
                          "{0},{1},{2}",
                          reader["STUDENTNAME"],
                          reader["STUDENTNUMBER"],
                          reader["STUDENTDESCRIPTION"]);

        ...
    }
}

---

There are a few ways - the most straight forward and probably the least desirable one is to modify the SQL:

command = new OleDbCommand("SELECT STUDENTNAME + ',' + STUDENTNUMBER + ',' ...

---

Using Linq.... using System.Linq

string result;
var reader=command.CreateReader();
if (reader.Read()) {
  result=String.Join(",",Enumerable.Range(0,reader.FieldCount).Select(x=>reader.IsDbNull(x) ? String.Empty : reader[x].ToString()).ToArray());
}

result will be null on no records or the value you want

---

I would use an OleDbDataReader, the concatentate the strings:

using (OleDbConnection connection = new OleDbConnection(connectionString))

    {
        OleDbCommand command = new OleDbCommand(queryString, connection);
        connection.Open();
        OleDbDataReader reader = command.ExecuteReader();

        while (reader.Read())
        {
            // put your logic here to concatenate the strings
            Console.WriteLine(string.Format("{0},{1},{2}",
                  reader["STUDENTNAME"],
                  reader["STUDENTNUMBER"],
                  reader["STUDENTDESCRIPTION"]);    
        }
        reader.Close();
    }

Hope this helps,

John