Oracle, SELECT IN and PreparedStatement.setArray

Question

I want to execute the following query: SELECT * FROM SOMETABLE WHERE IDFIELD IN (?)
The number of values in the IN list is variable. How can I do this with a prepared statement?
I am aware of the different alternatives:
1) Keep a cache of prepared statement for each sized list seen so far.
2) Keep a cache of prepared statements for different sizes (1, 5, 10, 20) and fill in the left over parameter positions with the copies first value.
They both have the disadvantage that there could be many prepared statements for each query that get used once, and never used again.
I have tried this:
stmt.execute ("CREATE OR REPLACE TYPE LONGINTLIST AS TABLE OF NUMBER(15)");
ArrayDescriptor desc = ArrayDescriptor.createDescriptor ("LONGINTLIST", conn);
long idValues [] = {2, 3, 4};
oracle.sql.ARRAY paramArray = new oracle.sql.ARRAY (desc, conn, idValues);
PreparedStatement query = conn.prepareStatement ("SELECT * FROM MYTABLE WHERE ID_FIELD IN (?)");
query.setArray (1, paramArray);
But Oracle gives a data conversion error.
I then tried this:
PreparedStatement query = conn.prepareStatement ("SELECT * FROM MYTABLE WHERE ID_FIELD IN (SELECT * FROM TABLE (?))");
This works and the rows are returned, but the Oracle optimizer does not like it very much, since it always does a full table scan even though there is a primary key index on ID_FIELD.
Any ideas?
I also tried this:
OraclePreparedStatement oraQuery = (OraclePreparedStatement) query;
oraQuery.setARRAY (1, paramArray);
But same behavior.
Roger Hernandez

Answer 1

Please re-read the original message. As I mentioned,
I am aware of the two commonly used alternatives.No actually the most used alternative is to build the SQL dynamically each time.
I know how to get both of them to work, and have used
both alternatives in the past. The downside to both
these approaches is that you need to save multiple
prepared statements for each query. What I am trying
to find is a way of having only one saved prepared
statement for a query having a variable number of IN
clause parameters.You could probably use a stored procedure that takes an 'array' and then do the processing in the stored proc to handle each array element.
However, your database might not support that stored procs or arrays. Or it might not cache it with arrays. And the overhead of creating the array structure or processing it in the proc might eat any savings that you might gain (even presuming there is any savings) by using a prepared statement in the first place. Of course given that you must be using an automated profiling tool and have a loaded test environment you should be able to easily determine if this method saves time or not.
Other than that there are no other solutions.