为什么返回空值？

Question

I sent the date value successfully. I checked from the 'Scoped Variables'.

This is a function in my bean that calls a function in helper:

public DataModel getFt() {
    ftDataModel = new ListDataModel((List) fthelper.getByBeginDate(beginDate));
    return ftDataModel;
}

This is the function that sent beginDate to Hibernate. But here it returns null. Why?

public FinancialTransactions getByBeginDate(String beginDate){            
    List<FinancialTransactions> FtList = null;        
    try {
        org.hibernate.Transaction tx = session.beginTransaction();
        Query q = session.createQuery("from FinancialTransactions where DATE='" + beginDate + "'");
        FtList = (List<FinancialTransactions>) q.list();

    } catch (Exception e) {
        e.printStackTrace();
    }
    return FtList.get(0);
}

Answer 1

One from these:

org.hibernate.Transaction tx = session.beginTransaction();
Query q = session.createQuery("from FinancialTransactions where DATE='" + beginDate + "'");

throw exception. Use debugger or simple System.out... to find which of those two.

Answer 2

You should use parameters in your query:

Query q = session.createQuery("from FinancialTransactions where DATE=:date").setParameter("date",beginDate);

There should be no inner exception or else FtList.get(0) would result in exception also.

My guess is formating. You use string representation of dates. Always a bad idea since there are many things that can go wrong in convertions.