Getting Startedwith pureQuery

Chapter 12 – Stored Procedures 245
corresponds to one of the parameters to the stored procedure call, and the order of the
parameters in the array is the same as the order of the parameters in the stored procedure
call. pureQuery populates the items in the array that correspond to OUT and INOUT
parameters with the updated values of those parameters. pureQuery does not return the
IN parameters; instead, it populates the items that correspond to IN parameters with Java
null as a placeholder.
If you want your application to call getOutputParms(), you must have it do so before the
StoredProcedureResult object has been closed. pureQuery automatically closes the
object when you retrieve the last query result. Therefore, if you want to get updated values
of OUT and INOUT parameters, have your application call getOutputParms() before it
retrieves any of the query results.
As an example, suppose that the SAMPLE database contains a procedure
EXAMPLE_PROCEDURE, as defined in Listing 12.1:
CREATE PROCEDURE SAMPLE.EXAMPLE_PROCEDURE
(IN parameter1 CHAR(8),
OUT parameter2 SMALLINT,
OUT parameter3 BIGINT)
LANGUAGE SQL
BEGIN
⁄* do something here *⁄
END
Listing 12.1 - The example stored procedure EXAMPLE_PROCEDURE
Assume that you use pureQuery to execute the procedure and create a
StoredProcedureResult object named storedProcedureResult containing the
results. You could store the output parameters in an array named outputParameters
like this:
Object[] outputParameters = storedProcedureResult.getOutputParms();
Observe that this stored procedure contains three parameters. Therefore, the array
outputParameters would have a length of three. The first parameter to the stored
procedure, parameter1 is an IN parameter, so the value of outputParameters[0]
would be null. The second parameter is an OUT parameters, so
outputParameters[1] would contain the updated value of parameter2. Similarly, the
third parameter is an OUT parameter, so outputParameters[2] would contain the
updated value of parameter3.
12.2.2 Getting the query results of the stored procedure
Stored procedures can have one or more query results. When pureQuery creates a
StoredProcedureResult object, it does not retrieve any query results from the
database. The StoredProcedureResult interface contains several getXXX methods,
each of which retrieves the next (or first) query result from the database and returns it in a