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如何设计实体关系来更好的实现跨级查询
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Jason Ye  
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 More options Dec 5 2006, 4:52 am
From: "Jason Ye" <ycch...@gmail.com>
Date: Tue, 05 Dec 2006 09:52:37 -0000
Local: Tues, Dec 5 2006 4:52 am
Subject: 如何设计实体关系来更好的实现跨级查询
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比如有Category、Product、Item三个实体，Category与Product之间，以及Product与Item之间都是1对多的关系。

如果我想直接查询某一个Category下面的所有Item，除了先返回Product[]，再返回Item[]，是否还有好的办法，可以减少实际产生的SQL 语句。


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Teddy  
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 More options Dec 5 2006, 6:36 am
From: Teddy <shijie...@gmail.com>
Date: Tue, 5 Dec 2006 19:36:49 +0800
Local: Tues, Dec 5 2006 6:36 am
Subject: Re: 如何设计实体关系来更好的实现跨级查询
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没有特别方便的办法，不过，一般，复杂（关联）查选，建议用存储过程查询或直接用sql查询，将返回的结果填充到实体。

例如，可以使用Gateway.FindArray<Entity>(string sql, params object[]
paramValues)重载使用自定义sql查询返回Items，但是注意，自定义sql的select的列的顺序必须和Item的属性定义一致。

Teddy

On 12/5/06, Jason Ye <ycch...@gmail.com> wrote:


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