createNativeQuery Question

[Tariq Ahsan]

Hi,

I am trying to use createNativeQuery to get certain column values which would be set to corresponding variables. Here's what I have in the code for this -

...

String sqlStmt = " select col1, col2, col3, col4  from (select col1, col2, col3, col4" +
			 "from table1" + 
			 "union " +
			 "select col1, col2, col3, col4" +
			 "from table2) " +
			 "where col1 = :col1";

List queryresults = em.createNativeQuery(sqlStmt).getResultList();

...

My problem is the query is an UNION of two tables as inline views and cannot typecast the List as one of the entity object. I tried to do something like -

List <table1> queryresults = em.createNativeQuery(sqlStmt).getResultList();
col1 = queryresults.get(0).getCol1();

...


But was getting ClassCastException probably as the datatype of table1 class did not match with the queryresults corresponding list value. I am guessing the queryresults value were being mapped incorrectly. But again I could be wrong.
Anyway, Is there any better way to extract these 4 column values from the list into separate variables?

Thanks

[Adrien Ruffie]

Hi Tariq,

do you have try to check the object type in your .getResultList() ?
List<Object> results = em.createNativeQuery(sqlStmt).getResultList();

for(Object obj: results){
//check the type of entity
System.out.println("entity: "+obj.getClass());
if(obj instanceof entityTable1){
//cast in entity or do something
}
if(obj instanceof entityTable2){
//cast in entity or do something
}
}





For separate variables :

Or you can subList you results try subList(beginIndex,endingIndex);
Or toArray() ?


Good day

[Tariq Ahsan]

Adrien,

Thanks for your prompt reply. I'll try those two option out.

- Tariq