请问一个关于C# WINFORM连接ORACL的问题·！

Question

private void button1_Click(object sender, EventArgs e)
        {
            string ConnectionString = "Data Source=zb12;user=gs;password=gs;";
            OracleConnection conn = new OracleConnection(ConnectionString);
          
                conn.Open();
                OracleCommand cmd = conn.CreateCommand();
                cmd.CommandText = "select * from MyTable";
                OracleDataReader odr = cmd.ExecuteReader();
                OracleDataAdapter adapter= new OracleDataAdapter(CommandText, conn);
                System.Data.DataTable dtTable = new System.Data.DataTable();
                adapter.Fill(dtTable);
                this.dataGridView1.DataSource = dtTable;
        }
我写了这个连接代码，想将“SELECT”的那些信息在dataGridView1上显示，但是提示CommandText上下文找不到~！请各位帮帮我啊~！

Answer 1

private void button1_Click(object sender, EventArgs e) 
        { 
            string ConnectionString = "Data Source=zb12;user=gs;password=gs;"; 
            OracleConnection conn = new OracleConnection(ConnectionString); 
          
                conn.Open();               
                OracleDataAdapter adapter= new OracleDataAdapter("select * from MyTable", conn); 
                System.Data.DataTable dtTable = new System.Data.DataTable(); 
                adapter.Fill(dtTable); 
                this.dataGridView1.DataSource = dtTable; 
        } 

Answer 2

OracleDataAdapter adapter= new OracleDataAdapter("select * from MyTable", conn); 
System.Data.DataTable dtTable = new System.Data.DataTable(); 
adapter.Fill(dtTable); 
this.dataGridView1.DataSource = dtTable; 

Answer 3

   string ConnectionString = "Data Source=zb12;user=gs;password=gs;"; 
            OracleConnection conn = new OracleConnection(ConnectionString); 
          
                conn.Open();                 OracleDataAdapter adapter= new OracleDataAdapter("select * from MyTable", conn); 
                System.Data.DataTable dtTable = new System.Data.DataTable(); 
                adapter.Fill(dtTable); 
                this.dataGridView1.DataSource = dtTable; 

Answer 4

如果是连接ORACL7 是不是用using System.Data.OleDb;连接代码请问怎样写啊？谢谢·！