Question

What is the best way to make a call to a stored procedure using JDBC if you only want to set some of the parameters?

If I was just using SQL, I could set the paramerers by name in the SQL to call the sproc. E.g. if I have a stored procedure with nine parameters and I wanted to set parameters 1,2 and 9, leaving the rest to their default values, I can run this SQL:

exec my_stored_procedure
    @parameter_1       = "ONE",
    @parameter_2       = "TWO",
    @parameter_9       = "NINE"

Using JDBC (Specifically jConnect 6.0), it seems that when using a CallableStatement, you have to set the parameters by their integer index, not their name. If I try the to create a CallableStatement for the above stored procedure, with 9 parameters, and only set parameters 1,2 and 9, like this:

myStoredProcedureCall = 
  sybConn.prepareCall("{call my_stored_procedure (?, ?, ?, ?, ?, ? , ?, ?, ?)}");
myStoredProcedureCall.setString(1, "ONE");
myStoredProcedureCall.setString(2, "TWO");
myStoredProcedureCall.setString(9, "NINE");
ResultSet paramResults = myStoredProcedureCall.executeQuery();

Then I get this SQLException thrown:

*** SQLException caught ***
SQLState: JZ0SA
Message:  JZ0SA: Prepared Statement: Input parameter not set, index: 2.
Vendor:   0

For some background on what I am trying to do, I need to create a process that receives information about products from a IBM MQ stream, and then creates a product in a 3rd application. The 3rd party application uses Sybase to store it’s data, and to create a product I need to call a stored procedure that has about 130 parameters. For the type of product I need to create, only about 15 of these parameters need to be set, the rest will be left to the default values.

Options I have considered are:

• Creating a custom stored procedure that sets only the values that I need, then calls the 3rd party product sproc.
• Setting default values for all parameters in the Java.

Surely there must be an easier way to do this?

Answer 1

This feature isn’t supported by JDBC. You will have to create an SQL string and execute that:

String sql = "exec my_stored_procedure\n@parameter_1 = ?,\n@parameter_2 = ?,\n@parameter_9 = ?";

PreparedStatement stmt = ...
stmt.setString( 1, "ONE" );
stmt.setString( 2, "TWO" );
stmt.setString( 3, "NINE" );
stmt.execute();

Remember: JDBC doesn’t try to understand the SQL that you’re sending to the database except for some special characters like {} and ?. I once wrote a JDBC “database” which would accept JavaScript snippets as “SQL”: I simply implemented DataSource, Connection and ResultSet and I could query my application’s memory model using the JDBC interface but with JavaScript as query language.