[Reprinted] Erwin concepts

(I recently learned Erwin and found this good article for literacy)

1. If you only create a document, you can choose to create only the logical view
2. For a project, you must use both the logical view and physical view.
3. Generally, logical view is used for document creation, while physical view is used to generate or export scripts.
4. Three connection lines between tables. The first is used to insert the primary key in table 1 to the foreign key in table 2, and the second is used as the primary key in table 2, the first method is rarely used to insert the primary key in table 1 to the foreign key in table 2, and the inserted primary key is not used as the primary key in table 2.
5. The names of the tables in logical and physical can be different. Generally, the names of tables in physical use English names in logical.
6. In [forward Engineer/Schema generation] of tools in physical view, you can select the project to be operated by checking the table on the right.
Click [Preview] to view the script. You can copy the script and change it. Click [report] to export the script and click [generate] to directly connect to the database, establish related Scheme
7. Right-click an entity in the logical view and select attributes to enter the page for adding column to the table. In general, select a basic type (domain) such as string, you can add a name. attribute name is the name column name in the logical view, which is the name used to generate the script. In general, the checkbox of the primary key is the place where the primary key is selected. You can set specific data types in datatype, such as varchar2 and number.
8. Right-click the index and constraint on entity and select key group to create the constraint.
9. Select datatype in attribute to select the column-related constraints in validate, and select the default value of this column in default.
10. The domains concept domain concept is supported in SQL Server. A bunch of domain names can be defined at the beginning of the script, then, the relevant domain names are referenced in the subsequent scripts, instead of the original data type.
For example: in the database design of a project, a lot of card numbers are used: So in Erwin's logical view, select domain and right-click? <Unkonwn>, new, you can create a new domain called cardseries. If you select property, you can select related properties for it. For example, if you select datatype as varchar (18), you can also select constraints for it.
This new domain can be conveniently used in this project.
11. About the concept of subject area when there are many design tables for the entire project, it is difficult to connect the relationships between all tables in a view. In this way, you need to split multiple areas in the subject area and put the relevant tables into the corresponding area to connect the tables, this is easier to design.
1> right-click on a corresponding area and go to view the corresponding view of that area.
2> right click-> property to set the tables in the current area. One of the more useful buttons is the last one (two ), you can add M-level ancester and N-level descendant related to the table to be added to the area at the same time. M and N can be selected by yourself, which is very convenient.
Note: The newly created entity in any non-primary area will have a copy in <main subject area>, and the deletion will also be performed at the same time.

Http://www.cnblogs.com/jplee/archive/2006/11/21/56...