⭐ 欢迎来到虫虫下载站！ | 📦 资源下载 📁 资源专辑 ℹ️ 关于我们
⭐ 虫虫下载站
📤 上传资源

📄 如何画数据库er图.htm

📁 数据库系统工程师的考点 难点 很值得一看的有
💻 HTM
📖 第 1 页 / 共 5 页
字号:
🔍
12345 
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- saved from url=(0125)http://www2.sdfi.edu.cn/netclass/jiaoan/2007/shujukuxitongyuanli/kewaizhidao/%C8%E7%BA%CE%BB%AD%CA%FD%BE%DD%BF%E2ER%CD%BC.htm -->
<HTML xmlns="http://www.w3.org/TR/REC-html40" xmlns:v = 
"urn:schemas-microsoft-com:vml" xmlns:o = 
"urn:schemas-microsoft-com:office:office" xmlns:w = 
"urn:schemas-microsoft-com:office:word"><HEAD><TITLE>如何画数据库ER图</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<META content=Word.Document name=ProgId>
<META content="MSHTML 6.00.2900.5512" name=GENERATOR>
<META content="Microsoft Word 11" name=Originator><LINK 
href="如何画数据库ER图.files/filelist.xml" rel=File-List><LINK 
href="如何画数据库ER图.files/editdata.mso" rel=Edit-Time-Data><!--[if !mso]>
<STYLE>v\:* {
	BEHAVIOR: url(#default#VML)
}
o\:* {
	BEHAVIOR: url(#default#VML)
}
w\:* {
	BEHAVIOR: url(#default#VML)
}
.shape {
	BEHAVIOR: url(#default#VML)
}
</STYLE>
<![endif]--><!--[if gte mso 9]><xml>
 <o:DocumentProperties>
  <o:Author>kang</o:Author>
  <o:LastAuthor>zy</o:LastAuthor>
  <o:Revision>2</o:Revision>
  <o:TotalTime>2</o:TotalTime>
  <o:Created>2007-05-29T11:47:00Z</o:Created>
  <o:LastSaved>2007-05-29T11:47:00Z</o:LastSaved>
  <o:Pages>1</o:Pages>
  <o:Words>125</o:Words>
  <o:Characters>719</o:Characters>
  <o:Lines>5</o:Lines>
  <o:Paragraphs>1</o:Paragraphs>
  <o:CharactersWithSpaces>843</o:CharactersWithSpaces>
  <o:Version>11.5606</o:Version>
 </o:DocumentProperties>
</xml><![endif]--><!--[if gte mso 9]><xml>
 <w:WordDocument>
  <w:SpellingState>Clean</w:SpellingState>
  <w:GrammarState>Clean</w:GrammarState>
  <w:PunctuationKerning/>
  <w:DrawingGridVerticalSpacing>7.8 磅</w:DrawingGridVerticalSpacing>
  <w:DisplayHorizontalDrawingGridEvery>0</w:DisplayHorizontalDrawingGridEvery>
  <w:DisplayVerticalDrawingGridEvery>2</w:DisplayVerticalDrawingGridEvery>
  <w:ValidateAgainstSchemas/>
  <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid>
  <w:IgnoreMixedContent>false</w:IgnoreMixedContent>
  <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText>
  <w:Compatibility>
   <w:SpaceForUL/>
   <w:BalanceSingleByteDoubleByteWidth/>
   <w:DoNotLeaveBackslashAlone/>
   <w:ULTrailSpace/>
   <w:DoNotExpandShiftReturn/>
   <w:AdjustLineHeightInTable/>
   <w:SelectEntireFieldWithStartOrEnd/>
   <w:UseWord2002TableStyleRules/>
   <w:UseFELayout/>
  </w:Compatibility>
  <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel>
 </w:WordDocument>
</xml><![endif]--><!--[if gte mso 9]><xml>
 <w:LatentStyles DefLockedState="false" LatentStyleCount="156">
 </w:LatentStyles>
</xml><![endif]-->
<STYLE>@font-face {
	font-family: 宋体;
}
@font-face {
	font-family: @宋体;
}
@page  {mso-page-border-surround-header: no; mso-page-border-surround-footer: no; }
@page Section1 {size: 595.3pt 841.9pt; margin: 72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin: 42.55pt; mso-footer-margin: 49.6pt; mso-paper-source: 0; layout-grid: 15.6pt; }
P.MsoNormal {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify; mso-bidi-font-size: 12.0pt; mso-style-parent: ""; mso-pagination: none; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt
}
LI.MsoNormal {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify; mso-bidi-font-size: 12.0pt; mso-style-parent: ""; mso-pagination: none; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt
}
DIV.MsoNormal {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify; mso-bidi-font-size: 12.0pt; mso-style-parent: ""; mso-pagination: none; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt
}
P.MsoDocumentMap {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; BACKGROUND: navy; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify; mso-bidi-font-size: 12.0pt; mso-pagination: none; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-style-noshow: yes
}
LI.MsoDocumentMap {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; BACKGROUND: navy; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify; mso-bidi-font-size: 12.0pt; mso-pagination: none; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-style-noshow: yes
}
DIV.MsoDocumentMap {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; BACKGROUND: navy; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: "Times New Roman"; TEXT-ALIGN: justify; mso-bidi-font-size: 12.0pt; mso-pagination: none; mso-fareast-font-family: 宋体; mso-font-kerning: 1.0pt; mso-style-noshow: yes
}
P.MsoPlainText {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 宋体; TEXT-ALIGN: justify; mso-pagination: none; mso-font-kerning: 1.0pt; mso-hansi-font-family: "Courier New"; mso-bidi-font-family: "Courier New"
}
LI.MsoPlainText {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 宋体; TEXT-ALIGN: justify; mso-pagination: none; mso-font-kerning: 1.0pt; mso-hansi-font-family: "Courier New"; mso-bidi-font-family: "Courier New"
}
DIV.MsoPlainText {
	TEXT-JUSTIFY: inter-ideograph; FONT-SIZE: 10.5pt; MARGIN: 0cm 0cm 0pt; FONT-FAMILY: 宋体; TEXT-ALIGN: justify; mso-pagination: none; mso-font-kerning: 1.0pt; mso-hansi-font-family: "Courier New"; mso-bidi-font-family: "Courier New"
}
SPAN.GramE {
	mso-style-name: ""; mso-gram-e: yes
}
DIV.Section1 {
	page: Section1
}
OL {
	MARGIN-BOTTOM: 0cm
}
UL {
	MARGIN-BOTTOM: 0cm
}
</STYLE>
<!--[if gte mso 10]>
<style>
 /* Style Definitions */
 table.MsoNormalTable
	{mso-style-name:普通表格;
	mso-tstyle-rowband-size:0;
	mso-tstyle-colband-size:0;
	mso-style-noshow:yes;
	mso-style-parent:"";
	mso-padding-alt:0cm 5.4pt 0cm 5.4pt;
	mso-para-margin:0cm;
	mso-para-margin-bottom:.0001pt;
	mso-pagination:widow-orphan;
	font-size:10.0pt;
	font-family:"Times New Roman";
	mso-ansi-language:#0400;
	mso-fareast-language:#0400;
	mso-bidi-language:#0400;}
</style>
<![endif]--><!--[if gte mso 9]><xml>
 <o:shapedefaults v:ext="edit" spidmax="2050"/>
</xml><![endif]--><!--[if gte mso 9]><xml>
 <o:shapelayout v:ext="edit">
  <o:idmap v:ext="edit" data="1"/>
  <o:regrouptable v:ext="edit">
   <o:entry new="1" old="0"/>
   <o:entry new="2" old="0"/>
   <o:entry new="3" old="2"/>
   <o:entry new="4" old="3"/>
   <o:entry new="5" old="4"/>
   <o:entry new="6" old="5"/>
   <o:entry new="7" old="0"/>
   <o:entry new="8" old="0"/>
   <o:entry new="9" old="0"/>
   <o:entry new="10" old="9"/>
   <o:entry new="11" old="0"/>
   <o:entry new="12" old="11"/>
   <o:entry new="13" old="0"/>
   <o:entry new="14" old="13"/>
   <o:entry new="15" old="0"/>
   <o:entry new="16" old="13"/>
   <o:entry new="17" old="15"/>
   <o:entry new="18" old="13"/>
   <o:entry new="19" old="0"/>
   <o:entry new="20" old="19"/>
  </o:regrouptable>
 </o:shapelayout></xml><![endif]--></HEAD>
<BODY lang=ZH-CN style="TEXT-JUSTIFY-TRIM: punctuation; tab-interval: 21.0pt">
<DIV class=Section1 style="LAYOUT-GRID:  15.6pt none">
<P class=MsoPlainText style="TEXT-ALIGN: center" align=center><B><SPAN 
style="FONT-SIZE: 12pt; mso-bidi-font-size: 10.5pt">如何画数据库<SPAN 
lang=EN-US>ER</SPAN>图<SPAN lang=EN-US><o:p></o:p></SPAN></SPAN></B></P>
<P class=MsoPlainText 
style="TEXT-INDENT: 21pt; mso-char-indent-count: 2.0">数据库设计中重要的一环首先就是概念设计，也就是说，要从实际问题出发，排除非本质的东西，抽象出现实的数据结构之客观规律——即画出数据结构图——<SPAN 
lang=EN-US>ER</SPAN>图。这是数据库设计的重点，也是数据库设计的难点。</P>
<P class=MsoPlainText 
style="TEXT-INDENT: 21pt; mso-char-indent-count: 2.0">那么，如何才能正确地反映客观现实，将<SPAN 
lang=EN-US>ER</SPAN>图画好呢？</P>
<P class=MsoPlainText><SPAN lang=EN-US><SPAN 
style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp; 
</SPAN></SPAN>答案是，必须进行正确的需求分析。那么如何进行需求分析呢？需求分析一般有两种方法，一种是结构化分析<SPAN 
lang=EN-US>(SA)</SPAN>，一种是面向对象分析<SPAN 
lang=EN-US>(OOA).</SPAN>通过这两种方法的实施以后，都可以得到比较正确的<SPAN 
lang=EN-US>ER</SPAN>图。现在以下面的实际问题为例，通过结构化分析<SPAN 
lang=EN-US>(SA)</SPAN>方法的应用，讲述如何得到比较正确的<SPAN lang=EN-US>ER</SPAN>图。</P>
<P class=MsoPlainText><SPAN lang=EN-US><SPAN 
style="mso-spacerun: yes">&nbsp;</SPAN>( </SPAN><SPAN class=GramE>一</SPAN><SPAN 
lang=EN-US> ) </SPAN>校务管理系统<SPAN lang=EN-US> </SPAN></P>
<P class=MsoPlainText>在要建立的系统中<SPAN lang=EN-US>,</SPAN>有以下功能：</P>
<P class=MsoPlainText><SPAN lang=EN-US>1.</SPAN>管理老师的功能：录入老师情况<SPAN 
lang=EN-US>(</SPAN>姓名<SPAN lang=EN-US>.</SPAN>地址<SPAN 
lang=EN-US>.</SPAN>所教课程<SPAN lang=EN-US>), </SPAN>老师缺课记录<SPAN 
lang=EN-US>(</SPAN>名字<SPAN lang=EN-US>.</SPAN>时间<SPAN lang=EN-US>.</SPAN>原因<SPAN 
lang=EN-US>. </SPAN>课程<SPAN lang=EN-US>) </SPAN></P>
<P class=MsoPlainText><SPAN lang=EN-US>2.</SPAN>管理学生的功能<SPAN lang=EN-US>: 
</SPAN>录入学生情况<SPAN lang=EN-US> ( </SPAN>姓名<SPAN lang=EN-US> . </SPAN>所选课程<SPAN 
lang=EN-US> . </SPAN>成绩<SPAN lang=EN-US> ) </SPAN></P>
<P class=MsoPlainText><SPAN lang=EN-US>3.</SPAN>教务主任的功能<SPAN lang=EN-US> : 
</SPAN>查询统计<SPAN lang=EN-US> 1: </SPAN>教师情况<SPAN lang=EN-US> 2: 
</SPAN>学生总成绩<SPAN lang=EN-US> 3: </SPAN>学生平均成绩<SPAN lang=EN-US> </SPAN></P>
<P class=MsoPlainText>要求：</P>
<P class=MsoPlainText><SPAN lang=EN-US>1</SPAN>）用结构化方法画出系统顶层图、<SPAN lang=EN-US> 
0 </SPAN>层图，数据字典。<SPAN lang=EN-US> </SPAN></P>
<P class=MsoPlainText><SPAN lang=EN-US>2</SPAN>）画出该系统的数据模型<SPAN 
lang=EN-US>ER</SPAN>图。<SPAN lang=EN-US> </SPAN></P>
<P class=MsoPlainText>一、结构化分析的需求分析</P>
<P class=MsoNormal 
style="MARGIN-LEFT: 18pt; TEXT-INDENT: -18pt; mso-list: l1 level1 lfo2; tab-stops: list 18.0pt"><![if !supportLists]><SPAN
12345

⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -