Cleveland
发表于 2025-3-21 17:19:54
书目名称Relational Database Technology影响因子(影响力)<br> http://impactfactor.cn/if/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology影响因子(影响力)学科排名<br> http://impactfactor.cn/ifr/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology网络公开度<br> http://impactfactor.cn/at/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology网络公开度学科排名<br> http://impactfactor.cn/atr/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology被引频次<br> http://impactfactor.cn/tc/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology被引频次学科排名<br> http://impactfactor.cn/tcr/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology年度引用<br> http://impactfactor.cn/ii/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology年度引用学科排名<br> http://impactfactor.cn/iir/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology读者反馈<br> http://impactfactor.cn/5y/?ISSN=BK0826094<br><br> <br><br>书目名称Relational Database Technology读者反馈学科排名<br> http://impactfactor.cn/5yr/?ISSN=BK0826094<br><br> <br><br>
STENT
发表于 2025-3-21 20:36:16
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健谈
发表于 2025-3-22 00:47:49
Logical Design,l entities including those which are in fact relationships. It requires little justification. In fact, we already showed that the hierarchical (unnormalized) model exhibits the insertion, deletion, and update anomalies. The reason is precisely the fact that more than one entity was represented by a
宽宏大量
发表于 2025-3-22 07:10:25
Data Integrity, constraints are specified during the logical design phase and are in fact a part of the model. Various general types of integrity constraints discussed so far have to do with functional dependencies and keys, multivalued dependencies, aggregation, generalization, and so on. In addition, there are m
Sad570
发表于 2025-3-22 10:49:44
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逗它小傻瓜
发表于 2025-3-22 15:01:01
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使无效
发表于 2025-3-22 20:41:34
https://doi.org/10.1007/978-1-4612-4922-1Processing; data model; database; modeling; optimization; programming; relational database
granite
发表于 2025-3-23 00:15:17
Introduction,Concepts, techniques, and tools of the technology that is the topic of this book are meant to be applied in a diversity of environments. In such an application environment, a diversity of users and their information needs are the reason for introducing the relational technology in the environment to satisfy those needs in the best possible way.
Cpr951
发表于 2025-3-23 05:07:23
Data Model,A model is a representation of a set of objects and their relationships. Such a representation is always the result of a process of abstraction. During that process relevant objects, relevant relationships among them, and relevant attributes of both objects and relationships are chosen.
Clumsy
发表于 2025-3-23 05:54:48
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