public SubQ(ClassMapping candidate,
    boolean subs,
    String alias) 
{
                       
        _candidate = candidate;
        _subs = subs;
        _alias = alias;
}

Constructor. Supply candidate, whether subclasses are included in the query, and the query alias.

 public  void acceptVisit(ExpressionVisitor visitor) 
{
        visitor.enter(this);
        for (int i = 0; i <  _exps.projections.length; i++)
            _exps.projections[i].acceptVisit(visitor);
        if (_exps.filter != null)
            _exps.filter.acceptVisit(visitor);
        for (int i = 0; i <  _exps.grouping.length; i++)
            _exps.grouping[i].acceptVisit(visitor);
        if (_exps.having != null)
            _exps.having.acceptVisit(visitor);
        for (int i = 0; i <  _exps.ordering.length; i++)
            _exps.ordering[i].acceptVisit(visitor);
        visitor.exit(this);
}

 public  void appendIsEmpty(Select sel,
    ExpContext ctx,
    ExpState state,
    SQLBuffer sql) 
{
        sql.append("NOT EXISTS ");
        appendTo(sel, ctx, state, sql, 0);
}

 public  void appendIsNotEmpty(Select sel,
    ExpContext ctx,
    ExpState state,
    SQLBuffer sql) 
{
        sql.append("EXISTS ");
        appendTo(sel, ctx, state, sql, 0);
}

 public  void appendSize(Select sel,
    ExpContext ctx,
    ExpState state,
    SQLBuffer sql) 
{
        appendTo(sel, ctx, state, sql, 0, true);
}

 public  void appendTo(Select sel,
    ExpContext ctx,
    ExpState state,
    SQLBuffer sql,
    int index) 
{
        appendTo(sel, ctx, state, sql, index, false);
}

 public  void calculateValue(Select sel,
    ExpContext ctx,
    ExpState state,
    Val other,
    ExpState otherState) 
{

}

 public ClassMapping getCandidate() 
{
        return _candidate;
}

Return the subquery candidate type.

 public String getCandidateAlias() 
{
        return _alias;
}

 public ClassMetaData getMetaData() 
{
        return _meta;
}

 public Class getType() 
{
        if (_exps != null) {
            if (_exps.projections.length == 0)
                return _candidate.getDescribedType();
            if (_exps.projections.length == 1)
                return _exps.projections[0].getType();
        }
        return _type;
}

 public  void groupBy(Select sel,
    ExpContext ctx,
    ExpState state) 
{
        sel.groupBy(newSQLBuffer(sel, ctx, state));
}

 public ExpState initialize(Select sel,
    ExpContext ctx,
    int flags) 
{
        if (_exps.projections.length == 1)
            return ((Val) _exps.projections[0]).initialize(sel, ctx, flags);
        return ExpState.NULL;
}

 public int length(Select sel,
    ExpContext ctx,
    ExpState state) 
{
        return 1;
}

 public Object load(ExpContext ctx,
    ExpState state,
    Result res) throws SQLException 
{
        return Filters.convert(res.getObject(this,
            JavaSQLTypes.JDBC_DEFAULT, null), getType());
}

 public  void orderBy(Select sel,
    ExpContext ctx,
    ExpState state,
    boolean asc) 
{
        sel.orderBy(newSQLBuffer(sel, ctx, state), asc, false);
}

 public  void select(Select sel,
    ExpContext ctx,
    ExpState state,
    boolean pks) 
{
        selectColumns(sel, ctx, state, pks);
}

 public  void selectColumns(Select sel,
    ExpContext ctx,
    ExpState state,
    boolean pks) 
{
        sel.select(newSQLBuffer(sel, ctx, state), this);
}

 public  void setImplicitType(Class type) 
{
        if (_exps != null && _exps.projections.length == 1)
            _exps.projections[0].setImplicitType(type);
        _type = type;
}

 public  void setMetaData(ClassMetaData meta) 
{
        _meta = meta;
}

 public  void setQueryExpressions(QueryExpressions query) 
{
        _exps = query;
}

 public Object toDataStoreValue(Select sel,
    ExpContext ctx,
    ExpState state,
    Object val) 
{
        if (_exps.projections.length == 0)
            return _candidate.toDataStoreValue(val,
                _candidate.getPrimaryKeyColumns(), ctx.store);
        if (_exps.projections.length == 1)
            return ((Val) _exps.projections[0]).toDataStoreValue(sel, ctx, 
                state, val);
        return val;
}