ER图与数据库表的关系是神马？
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解决时间 2021-02-14 13:23
- 提问者网友：像風在裏
- 2021-02-14 01:36
ER图与数据库表的关系是神马？
最佳答案
- 五星知识达人网友：老鼠爱大米
- 2021-02-14 01:51
ER图是基于ER模型（实体关系模型）画的，属于概念模型，是对现实世界的实体及其之间关系的抽象。
数据库表是属于数据模型，用来描述数据的结构关系。
通常我们数据库的设计要经过下面这个过程：
现实世界-〉概念模型-〉数据模型
一般项目的设计中，首先通过需求分析的人员根据客户抽象出 ER图，然后由数据库的设计人员根据ER图和用户对查询等方面的需求设计出数据库的表结构，以及相关的视图和索引。
数据库表是属于数据模型，用来描述数据的结构关系。
通常我们数据库的设计要经过下面这个过程：
现实世界-〉概念模型-〉数据模型
一般项目的设计中，首先通过需求分析的人员根据客户抽象出 ER图，然后由数据库的设计人员根据ER图和用户对查询等方面的需求设计出数据库的表结构，以及相关的视图和索引。
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- 1楼网友：醉吻情书
- 2021-02-14 04:28
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March, the days of spring thick ; March, the day that belongs to . Up day by day the sun was shining , the woman , but also a beautiful day together. Beauty is the cause of woman's life , health as a woman of great significance , only healthy women can make their own beauty shine forever . Day the morn , the spring . Take the moments of beauty ,true religion parfum, let us tell you some of the necessary 360 healthy women sense it,mont blanc rollerball pen!
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female genital because of their special physiological structure , are particularly vulnerable to bacterial invasion, menstrual cycles ,MBT Fora, Work stress, sexual and inappropriate hygiene ,thomas sabo reduziert, vaginal health may change in the weak acid environment to stimulate and gynecological inflammation. Chinese married women suffer from varying degrees of gynecological diseases ,thomas sabo Ringe, the incidence of cervical cancer in developed countries 6 times. Gynecological diseases have become a major threat to women's health killer. Attention to physical health, to develop good health care habits is the key to the prevention of gynecological diseases .
Journal of Preventive Medicine Branch of maternal and child health management expert , said: personal care products are divided into therapeutic and care , treatment and type of personal care products contain ingredients bactericidal drug is only suitable for use in gynecological inflammation phase Not suitable for everyday use when cleaning nursing . If long-term use therapeutic personal care products will hurt the vaginal lactobacilli , vaginal self-purification function of damage , but vulnerable to bacteria . Meanwhile, the strong bactericidal ingredients will harm the delicate genital skin and mucosal tissue,mbt schuhe bestellen, causing vaginal dryness and premature aging.
Topics related articles：
mont blanc rollerball pen S.H.E devil Slimming Treatment Rai
true religion How Breast diet
nike air max Simple exercises for 10 minutes, a sm
- 2楼网友：底特律间谍
- 2021-02-14 03:41
ER图是通过分析问题用一定的方法画出的类似于工作流程的图，但图中主要是流程中的实体（如：班级，教师，学生等）。然后你根据这些主体建立表 基本上就是一个实体一张表（这个具体看下书就会了）。所有的表组成数据库。
- 3楼网友：廢物販賣機
- 2021-02-14 02:42
画ER图就是在设计数据库。
ER图就是实体关系图（数据库关系图），主要完成了对系统中数据部分设计。
ER图就是实体关系图（数据库关系图），主要完成了对系统中数据部分设计。
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