asp.net-mvc-3 – 如何将ObjectResult转换为IQueryable？

我在asp.net mvc 3.0应用程序中使用实体框架.我正在使用表值函数在我的一个数据库表上进行全文搜索.我已将返回类型设置为Request类型的对象.然后,我将结果提供给表达式构建器,该构建器对用户有权访问的实体列表中的“请求”执行包含操作.这是代码.

List<int> UserEntities = db.UserEntities
                              .Where(x => x.UserID.Equals(usr.ID))
                              .Select(x => x.EntityID).ToList();

var requests = db.SearchRequest(keyword)
    .Where(BuildContainsExpression<Request,int>(x => x.EntityID,UserEntities));

//Expression Builder for Contains SQL functionality
static Expression<Func<TElement,bool>> BuildContainsExpression<TElement,TValue>(
     Expression<Func<TElement,TValue>> valueSelector,IEnumerable<TValue> values)
{
    if (null == valueSelector) { throw new ArgumentNullException("valueSelector"); }
    if (null == values) { throw new ArgumentNullException("values"); }
    ParameterExpression p = valueSelector.Parameters.Single();
    // p => valueSelector(p) == values[0] || valueSelector(p) == ...
    if (!values.Any())
    {
        return e => false;
    }
    var equals = values.Select(
            value => (Expression)Expression.Equal(
                                      valueSelector.Body,Expression.Constant(value,typeof(TValue))));
    var body = equals.Aggregate<Expression>(
                   (accumulate,equal) => Expression.Or(accumulate,equal));
    return Expression.Lambda<Func<TElement,bool>>(body,p);
}

第二行不会建立.编译器告诉我,SearchRequest过程正在返回ObjectResult但需要IQueryable.如何将ObjectResult转换为IQueryable？