Question

I use the below code to connect to my oracle DB and execute a query. The query I used in the example simply fetches a set of rows from a table. However, I keep getting an error message that “The table or view does not exist”. But, I am pretty sure that the table exists in the DB. Where am I going wrong?

 public void UpdateDatabase()
        {
            System.Data.OracleClient.OracleConnection conn = new System.Data.OracleClient.OracleConnection();
            conn.ConnectionString = "Data Source=(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.5.144)(PORT = 1521))(CONNECT_DATA =(SERVER = DEDICATED)(SERVICE_NAME = orcl)));UID=mwm;PWD=mwm";
            conn.Open();
            OracleCommand command = conn.CreateCommand();
            command.CommandText = "Select * from Task"; 
            command.ExecuteNonQuery();
            command.Dispose();
        }

The error is triggered when command.ExecuteNonQuery() is reached.

Answer 1

I think the problem is with command.ExecuteNonQuery();

Actually you are executing a query here therefore you should use either DataAdapter or DataReader.

public void UpdateDatabase()
{
   System.Data.OracleClient.OracleConnection conn = new    System.Data.OracleClient.OracleConnection();
  conn.ConnectionString = "Data Source=(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.5.144)(PORT = 1521))(CONNECT_DATA =(SERVER = DEDICATED)(SERVICE_NAME = orcl)));UID=mwm;PWD=mwm";
     conn.Open();
     OracleCommand command = conn.CreateCommand();            
     SqlDataAdapter a = new SqlDataAdapter("Select * from \"Task\"", command))            
     DataTable t = new DataTable();
     a.Fill(t);
     command.Dispose();
}