Is it possible to pass a null parameter to a stored procedure in Java JPA 2.1?

Question

Using the new JPA 2.1 stored procedure call, is there any way to pass a null parameter?

Here is an example usage:

StoredProcedureQuery storedProcedur         


        

Answer 1

You can create a method to positively enable all the calling parameters as the code below, it also works fine in case your StoredProcedureQuery contains out parameters. This helps you don't break the null parameter checking somewhere.

public void setStoreProcedureEnableNullParameters(StoredProcedureQuery storedProcedureQuery) {
    if (storedProcedureQuery == null || storedProcedureQuery.getParameters() == null)
        return;

    for (Parameter parameter : storedProcedureQuery.getParameters()) {
        ((ProcedureParameterImpl) parameter).enablePassingNulls(true);
    }
}

Then call

StoredProcedureQuery storedProcedure = entityManager.createStoredProcedureQuery("your_store_procedure")
    .registerStoredProcedureParameter("Param_1", String.class, ParameterMode.OUT)
    .registerStoredProcedureParameter("Param_2", String.class, ParameterMode.IN)
    .registerStoredProcedureParameter("Param_3", String.class, ParameterMode.IN);

// Remember you must call before setting the value for the parameters
setStoreProcedureEnableNullParameters(storedProcedure);

storedProcedure
    .setParameter("Param_2", null)
    .setParameter("Param_3", "Some value");
storedProcedure.execute();

String outValue = (String) storedProcedure.getOutputParameterValue("Param_1");