Map an entity to an Native SQL Query

Question

Is this possible to map a SQL Native query (instead of a table) with an Entity without annotations (using XML configuration)??

I know that i can make a View in the database and map this view as a workaround to this, but I try to avoid this solution because the Schema is automatically generated from the Entities model, and I would have to create the view manually afterwards.

I know also that with annotations there exist something like @SqlResultSetMapping, but I am not allowed to use annotations.

Answer 1

A view is the proper way. If you want to somehow store an SQL query in the database, and refer to its results regularly (as if it were a table), then that is precisely the description of a view.

So just create a view and map it.

If that does not solve your problem, please edit your answer to explain why a solution using a view is not practical. Maybe we can help you then.

Answer 2

For mapping legacy tables on an entity using Hibernate you could use a DAO method like this one:

public List<Audit> getAudits(Integer branchId, Integer locationId, Date fromDate, Date toDate, int first, int count, String sortProperty, boolean ascending) {

    // columns renamed to match sort properties and hibernate mapping
    StringBuilder query = new StringBuilder(
        "SELECT AUD_Number AS number,"
        + " AUD_Number_REL AS relationNumber,"
        + " AUD_Name_REL AS relationName,"
        + " AUD_Date AS date,"
        + " FROM audit WHERE 1");
        if (branchId!= null) {
            query.append(String.format(" AND AUD_Number_BRN = %s", branchId));
        }
        if (locationId!= null) {
            query.append(String.format(" AND AUD_Nummer_LOC = %s", locationId));
        }
        if (fromDate != null) {
            query.append(String.format(" AND AUD_Date >= %s", DateConverter.dateToSql(fromDate)));
        }
        if (toDate != null) {
            query.append(String.format(" AND AUD_Date <= %s", DateConverter.dateToSql(toDate)));
        }
        query.append(String.format(" ORDER BY %s %s", sortProperty, ascending ? "ASC" : "DESC"));
        query.append(String.format(" LIMIT %s, %s", first, count));
        return (List<Audit>) getSession().createSQLQuery(query.toString()).addEntity(Audit.class).list();
}

Meanwhile in mappings.hbm.xml:

<class name="Audit">
    <id name="number" type="integer" />
    <property name="relationNumber" type="integer" />
    <property name="relationName" type="string" />
    <property name="date" type="datetime" />
</class>
etc...

Omitting spring context for brevity.

Does this help?