Re: 帮人问个SQL语句

Article View: cn.comp.database

Article #67

#67

From: Lee Put
Date: Thu, 29 Jun 2006 18:14

13 lines
2213 bytes

> 现在偶要得到下面查询结果
>
>
> ClassName   ProductName
> Class_a1   Product_a1, Product_a2
> Class_b1   Product_b1
> Class_c1   Product_c1, Product_c2, Product_c3
> Class_d1
>
> 请问这样的SELECT语句要怎么写？

这里面你的结果要求也算是有问题的，因为SELECT的操作对象都是关系，关系本身来讲可以俗称为一张二维表，所以你的结果要求应该是：
ClassName   ProductName
Class_a1 Product_a1
Class_a1 Product_a2
Class_b1 Product_b1
Class_c1 Product_c1
Class_c1 Product_c2
Class_c1 Product_c3
Class_d1 NULL

那么针对这个结果来讲，我们操作就可以直接用连接就行了！
如下：
SELECT ClassName, ProductName FROM Class, Product WHILE
Class.ClassID=Product.ClassID;

这样子可以满足上述要求了！如果你的数据库还有进下不要求的话，那么还需要进一步把SQL查询进行加工。

Technical Details

Message-ID: <1151604847.535053.91780@m73g2000cwd.googlegroups.com>

Path: arc1-ca.pugleaf.net!g2news2.google.com!postnews.google.com!m73g2000cwd.googlegroups.com!not-for-mail

References: <e7d5na$s4h$1@news.yaako.com>

Show Full Headers

Complete Article Headers

X-Google-Thread: 1106d1,c944b8eba60875d8
X-Google-Attributes: gid1106d1,public
X-Google-Language: Chinese,GB
Path: arc1-ca.pugleaf.net!g2news2.google.com!postnews.google.com!m73g2000cwd.googlegroups.com!not-for-mail
From: "Lee Put" <urgentmind@gmail.com>
Newsgroups: cn.comp.database
Subject: Re: 帮人问个SQL语句
Date: 29 Jun 2006 11:14:07 -0700
Organization: http://groups.google.com
Lines: 14
Message-ID: <1151604847.535053.91780@m73g2000cwd.googlegroups.com>
References: <e7d5na$s4h$1@news.yaako.com>
NNTP-Posting-Host: 222.244.117.38
Mime-Version: 1.0
Content-Type: text/plain; charset="gb2312"
Content-Transfer-Encoding: base64
X-Trace: posting.google.com 1151604853 29734 127.0.0.1 (29 Jun 2006 18:14:13 GMT)
X-Complaints-To: groups-abuse@google.com
NNTP-Posting-Date: Thu, 29 Jun 2006 18:14:13 +0000 (UTC)
In-Reply-To: <e7d5na$s4h$1@news.yaako.com>
User-Agent: G2/0.2
X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.0; zh-CN; rv:1.8.0.4) Gecko/20060508 Firefox/1.5.0.4,gzip(gfe),gzip(gfe)
Complaints-To: groups-abuse@google.com
Injection-Info: m73g2000cwd.googlegroups.com; posting-host=222.244.117.38;
   posting-account=ZaKbcA0AAAAGPFf5Me9tOZ4A5KimBDJw

Reply to Parent Message