create or replace TYPE EMP_CSV_OBJ AS OBJECT
    (
       FirstName VARCHAR2(50),
       LastName VARCHAR2(50),
      MiddleName VARCHAR2(50)
   );

create or replace TYPE EMP_CSV_TABLE
   AS TABLE OF emp_csv_obj;

CREATE OR REPLACE PROCEDURE INSERT_EMPLOYEE(empCsv IN EMP_CSV_TABLE) AS
    BEGIN
      MERGE INTO Employees pt
      USING (select * from table(empCsv)) src
      ON (pt.FIRST_NAME = src.FIRSTNAME)
     WHEN NOT MATCHED THEN INSERT
      (pt.FIRST_NAME, pt.LAST_NAME, pt.MIDDLE_NAME)
      VALUES (src.FirstName , src.LastName , src.MIDDLENAME);
  
   -- COMMIT;
  END;

DataTable dt = new DataTable();
dt .Columns.Add("FirstName", typeof(string));
dt .Columns.Add("LastName", typeof(string));
dt .Columns.Add("MiddleName", typeof(string));
dt.Rows.Add("AALI", "THOR", "R");
dt.Rows.Add("Dereanna", "CARTER", "Michelle");

string connectionString = "myconstring";
using (OracleConnection connection = new OracleConnection(connectionString))
{
   connection.Open();
   using (OracleCommand cmd = new OracleCommand("INSERT_EMPLOYEE", connection))
   {
     cmd.CommandType = CommandType.StoredProcedure;
     OracleParameter param = new OracleParameter();
     param.OracleDbType = OracleDbType.Array;
     param.UdtTypeName = "EMP_CSV_TABLE";
     param.Value = dt; 
     cmd.Parameters.Add(param);
     cmd.ExecuteNonQuery();
   }
 }