Step-by-Step UML modeling Series 7. Data Model digraphs)

Overview

The data model profile is a UML extension of Enterprise impact ect to support relational database modeling. It includes some custom extensions, such as tables, database charts, table keys, triggers and constraints. It is a technology used to model relational databases in UML.

Data Modeling not only supports object attribute modeling (such as E-R diagram), but also modeling data behavior (such as trigger, stored procedure ). the following concepts are designed during Database Design:

Schema, primary key primary, foreign key, relational relationship, constraints constraint, Index, trigger, stored procedure, view.

Table)

A table is the most basic model structure of a relational database.

Table Index)

Indicates the logical sequence of records created by a keyword segment or expression in a table file. It is a list composed of a series of record numbers, providing quick access to data. The index does not change the physical sequence of records in the table.

 

Table trigger)

When performing operations such as update, insert, and delete on a table, SQL Server automatically runs the SQL statement defined by the trigger, this ensures that data processing must comply with the rules defined by these SQL statements.
The trigger is mainly used to achieve complex integrity of reference and data consistency that cannot be guaranteed by the primary key and foreign key.

Table Constraints)

Column constraints ensure data validity.

View)

A view is a table exported from one or more tables or views. Its structure and data are based on table queries.

 

 

Let's look at another example.

 

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Author: Spring Yang

Source: http://www.cnblogs.com/springyangwc/

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