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Setting a collection parameter as a list for column values

I'm trying to write a query with a Collection parameter. It is assumed that query would turn this collection to a column of its values for the further operations. I'm using Spring, so now my query looks like:
#Query(value = "SELECT id FROM unnest(array[?1]) id", nativeQuery = true)
List<Object> getIds(Collection<String> ids);
It doesn't work, because Hibernate set collections as parameters in braces, so the real query will be send to DB:
SELECT id FROM unnest(array[('1', '2')]) id
This is not a valid query, the error is raising:
ERROR: a column definition list is required for functions returning
"record" SQL state: 42601
Right version of it must be:
SELECT id FROM unnest(array['1', '2']) id
So please can anybody tell me, if there is a way I could set a collection as query parameter without braces? Or maybe there is an another way to turn collection to column?

How to get only two column result instead of entire row?

My query like this,
String sql="select p.productName,p.extendedFlag from product p where productId=? and productVersion=?";
SqlQuery sqlQuery=session.createSQLQuery(sql).addEntity(Product.class);
sqlQuery.setParameter(0,"newprofin2");
sqlQuery.setParameter(1,"newprofin2");
List product =sqlQuery.list();//error at this line
Product p=(Product)product.get(0);
please Help me,
and i am using Hibernate 3.

If you want to return the result as an entity you need to use "select * ..." (so hibernate can map all the column annotations) otherwise you have to stick with selecting only scalar values that are not mapped to the entity and need to be processed on a column basis.
Examples:
http://www.tutorialspoint.com/hibernate/hibernate_native_sql.htm

Need help regarding HIbernate count query

We have a use case to count no. of rows returned by actual query. I am not getting how can I get it using criteria in hibernate.
For example suppose I want to run query
select sum(TOTAL_EARNINGS) from table where column1 = 'value1' group by column2);
Along with this query result I also want to get total rows return by above query(above query may have rownum limit also but for total rows I have to ignore rownum limit).
select count(*) from (select sum(TOTAL_EARNINGS) from table
where column1 = 'value1' group by column2);
Is there any easy way of getting this data. I am fine with running separate query to get count data but I am not getting how can I write this in hibernate using criteria. I can't even see any option in SubQueries which I can use

In general with criteria you can use projections.
You can do so, if you have an entity "Your" mapped by Hibernate:
Edited:
Accordingly to your comment, you need two results, a total count and a group by results.
//the group by results...
List result1 = session.createCriteria("Your.class").setProjection(Projections.projectionList()
.add(Projections.groupProperty("column2"))
.add(Projections.sum("totalErnings"))
).list();
//the total count result
return (Integer) session.createCriteria("Your.class").add(Restrictions.eq("column1", val)).setProjection(Projections.rowCount()).uniqueResult();

Criteria generates SQL Query correctly but it does not return anything

A criteria is used to retrieve data from database. It generates SQL Query perfectly, which is tested on mySql separately and the records are loaded correctly;However, when using Criterial.list() it gives me an empty list.
I have checked my DB connections, and they are all correct. What would have caused this problem?
UPDATED
Here is my code:
accCr = DetachedCriteria.forClass(TSESpotInvestorAccount.class, "acc");
accCr.setResultTransformer(DetachedCriteria.DISTINCT_ROOT_ENTITY);
accCr.add(Restrictions.eq("exchangeDepositNo", filter.getBc()));
accCr.setProjection(Projections.id());
List accIds = getHibernateTemplate().findByCriteria(accCr);

Your code doesn't make much sense:
accCr.setResultTransformer(DetachedCriteria.DISTINCT_ROOT_ENTITY);
The above line says that the query is supposed to return entities (with, potentially, joined entities), and that Hibernate should return only distinct entities
accCr.setProjection(Projections.id());
The above line says that the query must only return one scalar column: the ID of the root entity.
If what you want is a list of IDs, then don't set the distinct root entity result transformer.

Hibernate Criteria -- return records where column is distinct

Sample database table:
ID = 1, msgFrom = 'Hello', foobar = 'meh'
ID = 2, msgFrom = 'Goodbye', foobar = 'comments'
ID = 3, msgFrom = 'Hello', foobar = 'response'
Sample desired output (generated by hibernate query):
ID = 1, msgFrom = 'Hello', foobar = 'meh'
ID = 2, msgFrom = 'Goodbye', foobar = 'comments'
In the above example, the third record would be excluded from the results since the msgFrom column is the same. Let's say the Java/Hibernate class is called Message. I would like the results to be returned as a list of Message objects (or Objects that can be cast to Message, anyway). I want to use the Criteria API if possible. I saw this example on SO and it seems similar but I cannot implement it correctly as of yet.
select e from Message e
where e.msgFrom IN (select distinct m.msgFrom
from Message m
WHERE m.msgTo = ?
AND m.msgCheck = 0");
The reason I am doing this is to have the filtering of distinct records done on the database, so I am not interested in answers where I have to filter anything on the application server.
edit: Article showing basically what I want to do. http://oscarvalles.wordpress.com/2008/01/28/sql-distinct-on-one-column-only/

Please try this and let me know
DetachedCriteria msgFromCriteria = DetachedCriteria.forClass(Message.class);
ProjectionList properties = Projections.projectionList();
properties.add(Projections.groupProperty("messageFrom"));
properties.add(Projections.min("id"),"id");
msgFromCriteria.setProjection(properties);
Criteria criteria = s.createCriteria(Message.class);
criteria.add(Subqueries.propertiesIn(new String[]{"messageFrom","id"},
msgFromCriteria));
List<Message> list = criteria.list();
for(Message message:list){
System.out.println(message.getId()
+"-------"
+message.getMessageFrom()
+"-----"
+message.getFoobar());
}

The difficulty with this query is not so much with Hibernate, per se, but with the relational model in general. In the example, you say you expect rows 1 and 2, but why wouldn't you just as easily expect rows 2 and 3? It would be an arbitrary decision whether to return row 1 or row 3 since they both have the same value in the msgFrom field. Databases won't make arbitrary decisions like this. That's why distinct must be applied to the entire list of select columns, not a subset. There are database-specific ways of grabbing the first matching rows. For example, have a look at
SELECT DISTINCT on one column
Sometimes there will be a date column that you can use to decide which of the matching rows to return, but again the queries get somewhat complex:
How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
Fetch the row which has the Max value for a column
If you don't care about any of the other columns, you can just use a simple distinct, combined with Hibernate's constructor syntax (not tested):
select new Message(msgFrom) from (select distinct msgFrom from Message)
but you have to accept throwing away all the other columns.
In the end, I often end up just doing this in code as a post query filter. Another option is to create a another table, say CurrentMessage, that includes msgFrom as part of the key. There will be more work in keeping this table up to date (you need to update a row everytime you add a row to the Message table) but querying will be much easier.

DetachedCriteria msgFromCriteria = DetachedCriteria.forClass(Message.class);
msgFromCriteria.setProjection(Projections.distinct(Projections.property("msgFrom")));
....
Criteria criteria = getSession().createCriteria(Message.class);
criteria.add(Subqueries.propertyIn("msgFrom", msgFromCriteria));
criteria.list();