Sendings typed Arrays (ArrayBindCount) with DBNull's in the middle

Question

Hello again,
I wanted to share another problem I had using ODP against Oracle.
I need to insert multiple rows into table which allows some parameters to be null.
Table schema:
CREATE TABLE ANNOTATIONS
ANNOTATIONID NUMBER,
ANNOTATIONNAME NVARCHAR2(64) // this can be null (the same with value types like number)
Stored proc:
procedure ANNOTATIONSINSERT( in_ANNOTATIONID in ANNOTATIONS.ANNOTATIONID%type , in_ANNOTATIONNAME in ANNOTATIONS.ANNOTATIONNAME%type)
AS
BEGIN
INSERT INTO ANNOTATIONS ( ANNOTATIONID, ANNOTATIONNAME)
END;
Since I use ArrayBindCount mechanism, I use typed arrays (as the type of table column)
for example (int arrays) and send them to appropriate stored proc.
What happens when I want to put a DBNull value into one of the integer arrays?
(I need to use some conversion function: but there is no convert from System.DBNull!)
Here is a solution I found to this problem: it works although ODP doesn't support
object types
private void testCase()
     OracleConnection connection = new OracleConnection(some connection string);
     OracleCommand command = null; // = new OracleCommand("");//, connection);
     BuildANNOTATIONSINSERT(ref command); // I build here command and command parameters
     int total = 20;
     Random random = new Random();
     object [] iData = new object[total]; // YES, instantiate object arrays! and put in arrays true values
     object [] sData = new object[total];
     int data;
     for (int index=0; index<total; index++)
          data = random.Next(40000); // generate some random data
          iData[index] = data;
          if (data%4==0)
               sData[index] = System.DBNull.Value; // some of the data include null values
          else
               sData[index] = iData[index].ToString();
     try
          connection.Open();
          IDbTransaction txn = connection.BeginTransaction();
          command.Parameters[0].Value = iData;
          command.Parameters[1].Value = sData;
          command.Connection = connection;
          command.ArrayBindCount = total;
          command.ExecuteNonQuery();
          txn.Commit();
          connection.Close();
     catch (Exception eee)
          MessageBox.Show(eee.Message);
Should this work, I'm afraid to supply a functionality that works today: to a customer, and at the next
version of ODP, it will stop working. (and nobody will know why)
I can also use an error code for any type. (I can decide that -1 is error for NUMBER type and null for string types)
but I don't want to use that. Usage of objects is also costly (-20% speed performance): it seems that there is
some encapsulation of types in the core of ODP: byte[][] (also works) etc.
What is the proper way to do what I want, so it will be safe in the next versions of ODP?
Thanks!

Answer 1

Amir,
ODP.NET accepts array (object array) for array binding. However, passing object array is slower because of the boxing and unboxing of types in .NET (this is not ODP.NET behavior, but .NET). You can pass a type array for array binding, and that should be faster than an object array (boxing and unboxing won't happen). For example, passing an int[] should be faster than object[] for an Oracle Number type.
However, it is not possible to assign the DBNull.Null value to an element in the type array. In this case, you should make use of the OracleParameter.ArrayBindStatus to inform ODP.NET how to bind the elements in the type array. For example, if the 3rd element is to be treated as Null value, the code will looks like this:
int[] ints = new Int32[10];
param.ArrayBindStatus = new OracleParameterStatus[10];
for (int i = 0; i &lt; 10; i++)
param.ArrayBindStatus[i] = OracleParameterStatus.Success;
//Now tell ODP.NET that the 3rd should treat as Null value
param.ArrayBindStatus[2] = OracleParameterStatus.NullInsert;
If you use object array instead, setting the element to DBNull.Null should work. But as we mentioned, using object array will then be slower.
Let us know if we've any question regarding this.
Thanks
Martha