Table name as parameter in HQL

Question

Let's assume we have the HQL query:

String ageQuery = "select age from people where name = :name";

Session session = getSession();
Query query = session.
        createSQLQuery(nameQuery).
        setParameter("name", "Thomas");
// query.list(); returns the result

But what if I want to parametrize the table name? One can't use it like this:

String ageQuery = "select :table from people where name = :name";

Session session = getSession();
Query query = session.
        createSQLQuery(ageQuery).
        setParameter("table", "age").
        setParameter("name", "Thomas");

I've applied the workaround:

String ageQuery = "select :table: from people where name = :name";

Session session = getSession();
Query query = session.
        createSQLQuery(ageQuery.
        replace(":table:", "age")).
        setParameter("name", "Thomas");

... but I don't really like it. Is there any other solution?

Answer 1

You can't define table name as parameter; you have to build statement with string concatenation in old fashion way.
Your workaround is not a workaround, but the only way to proceed.
Is an issue similar to the one described in Incorrect syntax near '@P0'. exception when create and drop Login in MSSQL

Answer 2

I use dynamic queries below:

var query = session.CreateQuery(String.Format("update {0} set {1} = :updatevalue where {2} = :wherevalue",
    MyClassMapping<UserEntity>.GetEntityName(),
    MyClassMapping<UserEntity>.GetPropertyName(x => x.LastLoginTime),
    MyClassMapping<UserEntity>.GetPropertyName(x => x.UserKey)))
    .SetParameter("updatevalue", DateTime.Now)
    .SetParameter("wherevalue", user.UserKey);
int rowsAffected = query.ExecuteUpdate();