Datareader
is used to read data from a database. Before reading the data, you should
create a connection and write your query to fetch data from the database
using command object.
Once these two steps are done, you can use datareader to read the resultant
rows of the query defined in the command object. Here is a simple example:
class sampleClass
{
public static void Main() {
string sampleConnString = “Persist Security Info = False; Initial
Catalog =
sampleDB;Data Source= sampleDataServer; User ID = scott; password=tiger”;
SqlConnection sampleConn = new SQLConnection(sampleConnString);
string sampleQuery = “select rollNo, studName from student”;
SqlCommand sampleCmd = new SqlCommand(sampleQuery, sampleConn);
sampleConn.Open();
SqlDataReader sampleReader = sampleCmd.ExecuteReader();
if(sampleReader.HasRows) {
while (sampleReader.Read()) {
Console.WriteLine(“RollNo: {0}, Name:{1}”,
sampleReader.GetString(0), sampleReader.GetString(1));
}
}
sampleReader.Close();
sampleConn.Close();
