ObjectQuery for Castle.ActiveRecord 使用指南（1）：Joins

ObjectQuery支持HQL的各种Join操作，例如下列的HQL：

from Eg.Cat as cat 
    inner join cat.Mate as mate
    left outer join cat.Kittens as kitten

from Eg.Cat as cat left join cat.Mate.Kittens as kittens

from Formula form full join form.Parameter param

用ObjectQuery可以这样写：           

Query.From(DB.Cat

    .InnerJoin(DB.Mate, DB.Cat.Mate)

    .LeftOuterJoin(DB.Kitten, DB.Cat.Kittens))

Query.From(DB.Cat.LeftJoin(DB.Kitten, DB.Cat.Mate.Kittens))

Query.From(DB.Formula.FullJoin(DB.Parameter, DB.Formula.Parameter))

支持的Joins类型有：

• inner join

• left outer join

• right outer join

• full join (not usually useful)