dhs cdm

Conceptual Data ModelThe conceptual data Model (conceptual data MODEL,CDM): Expresses the overall logical structure of the data, which is independent of any software and data storage structure, that is, it is just a common language for system analysts, application designers, maintenance personnel and users to understand each other. does not target specific database platforms (such as Oracle or SQL Server) and tools (PowerBuilder). The objects containe

CDM is the first model created by most developers when using PD, and is also the highest abstraction of the entire database design. CDM is built on the traditional ERTU model theory. ERTU has three main elements: solid shape, attributes, and relationships. The entity type corresponds to the entity in the CDM, and the attribute corresponds to the attribute of each

Note: All essays on this blog are original on cnblogs by eaglefish. You are welcome to reprint them, but please indicate the source.CDM is the first model created by most developers when using PD, and is also the highest abstraction of the entire database design. CDM is built on the traditional ERTU model theory. ERTU has three main elements: solid shape, attributes, and relationships. The entity type corresponds to the entity in the

Note: All essays on this blog are original on cnblogs by eaglefish. You are welcome to reprint them, but please indicate the source. CDM is the first model created by most developers when using PD, and is also the highest abstraction of the entire database design. CDM is built on the traditional ERTU model theory. ERTU has three main elements: solid shape, attributes, and relationships. The entity type

In the process of writing documents, there must be a system database design. How should we design the database? First, let's explain a concept: CDM: The concept Data Model (CDM) is used to design the process from the concept layer. In the concept layer, you do not need to consider the actual physical implementation details. CDM describes the overall logical struc

CDM is the first model created by most developers when using PD, and is also the highest abstraction of the entire database design. CDM is built on the traditional ERTU model theory. ERTU has three main elements: solid shape, attributes, and relationships. The entity type corresponds to the entity in the CDM, and the attribute corresponds to the attribute of each

Label:Some time ago with the next powerdesigner do some auxiliary work, here specifically summarized: For the migration of the SQL between the CDM, PDM, SQL and database tables between different databases, the first thing to know is what they are used for, a simple description here, not a detailed explanation. CDM: Conceptual data Model. CDM is to describe the E-

Label: For the migration of the SQL between the CDM, PDM, SQL and database tables between different databases, the first thing to know is what they are used for, a simple description here, not a detailed explanation. CDM: Conceptual data Model. CDM is to describe the E-r diagram in its own way. It does not take into account the physical implementation details, on

ConceptualDataModel: conceptual data model, which is based on the Entity-RelationShip (E-R) theory and is expanded. It starts from the user Conceptual Data Model: Conceptual Data Model, which is based on the Entity-RelationShip (E-R) theory and is expanded. It starts from the user For more information about PowerDesigner, see: PowerDesigner 15 Overview This article mainly describes the CDM model and its usage. 1. Overview of concept data model (

For more information about PowerDesigner, see: PowerDesigner 15 Overview This article mainly describes the CDM model and its usage. 1. Overview of concept data model (CDM)Conceptual Data Model: Conceptual Data Model, which is based on the Entity-RelationShip (E-R) theory and is expanded. It models information from the user's point of view and is mainly used for Conceptual Design of databases. Generally, pe

Label:Source: http://jbeduhai.iteye.com/blog/338579As the picture is not displayed, please download the attachment if you want to see the contents and picture details.PowerDesigner Data Model (conversion process for cdm-pdm-sql scripts)In the development process will often encounter to do a module function, first of all, you need to draw a e-r diagram first,A lot of friends are not very familiar with the E-r map, or some friends in the development of

Conceptual Data ModelThe conceptual Data Model (CDM) helps you analyze the conceptual structure of an information system and then identifies the major entities that need to be described, the attributes in those entities, and the relationships between those entities. Conceptual data models are more abstract than logical or physical data models.Logical Data ModelThe logical Data Model (LDM) helps you analyze the structure of the information system, inde

real world into a conceptual world, and then convert the conceptual world into a machine world. In other words, objective objects in the real world are first abstracted as entities and relationship. They do not depend on a specific computer system or a DBMS system, this model is what we call CDM, and then converts CDM to the data model supported by a DBMS on the computer. This model is the physical data mo

[Reprint] Original Source: http://blog.sina.com.cn/s/blog_544a29990100doqn.html Note: ATM and CDM used by commercial banks in China are mainly produced in Germany and Japan. ATM self-help cash machines are also upgraded from old-fashioned machines to new machines and CDM self-help cash machines to CDT, replace it with the CRS self-help deposit and withdrawal machine!Currently, the most advanced machines in

Powerdesigner defines cdm, ldm, and pdmConceptual Data Model The conceptual data model (CDM) helps you analyze the conceptual structure of the information system, and then identify the main entities to be described, the attributes in these entities and the relationships between these entities. The conceptual data model is more abstract than the logical or physical data model.Logical Data Model The Logical

This data item was already used in a primary identifier. Normalization rules prevent ...The methods to be handled are:"Tool"-〉 "model Option"-〉 "model Setting" on the menu barCancel the "Unique Code" option box in the "Data Item" box on the right.If you are prompted for a property error when converting from CDM-〉PDM, please cancel the check model hook in the PDM GENERATION options.PowerDesigner the default method for removing a primary key with the sa

The concept data model (ConceptualDataModel) is also called the information model. It is based on the object-link theory and expanded. The concept Data Model (Conceptual Data Model) is also known as the information Model. It is based on the object-link theory and expanded. The concept Data Model (Conceptual Data Model) is also known as the information Model. It is based on the object-link theory and expanded. It models the information Data from the user's perspective, it is mainly used for C

In PD, the CDM model is created. A digoal has two tables, and the fields cannot be repeated? Tool-model options-model settings remove the unique code under data item There is also a "allow reuse" check box. We recommend that you remove this check box. In the future, don't worry about the problem of field dynamic modification in the model. I just tried it, even if you copy a field from one table to another, the two fields are not modified! We re

automatically created by relational Relationship, and do not need to be manually created. Otherwise, redundant keys will be generated. Therefore, when designing, pay attention to the fields of the object and the relationship between objects, especially the many-to-many and dependency relationships. Note the following before converting CDM to PDM: The digoal name cannot be changed. In the tree chart, if you select the red Symbol to overwrite the modif

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