I have an element which is created as a table. In the "Element Properties" window, I see the Type is Class and Stereotype is table. For other similar tables, the Type is Table and Stereotype is table. Something seems to be icky with this particular instance.
However, when I run the following script
var element as EA.Element;
element = Repository.GetTreeSelectedObject();
Session.Output(element.Type);
The result is (for both tables!) Class. I thought to outsmart the EA UI by programmatically setting the type, but as both tables (the OK table and the "broken" table) both produce Class when asked for the .Type, I'm hesitant to set the .Type using a script.
I have thought about removing this table and re-adding a new one, but this is tedious as the table has a lot of connections.
How to change the Type of this particular "broken" table to "Table"?
The problem is that both «table» stereotypes are not the same.
The one where the type indicates Table is the correct one.
The other one is a rogue one.
Steps to solve this:
Remove the rogue stereotype from the internal stereotype list Configure | Reference Data | UML Types (to prevent the problem from happening again)
Change the stereotype from the problematic element to the stereotype «table» from the UML profile EAUML. In a script you can do this by setting the property EA.Element.StereotypeEx to the qualified name: EAUML::table). Manually you can use the [...] button to select the correct stereotype from the correct profile.
Related
I'm trying to model the following relationships between entities, mainly consisting of a partial, disjoint generalization.
original EERD
'mapped' to relational
Since I didn't need the subclasses to have any particular attributes I decided to use the "single table inheritance" approach, added the "type" field and moved the relationships towards the parent.
After that I had two choices to make:
1- type for the "business type" attribute
2- way to constraint participation to at most one of the 4 relationships based on the type attribute
For the sake of portability and extensibility I decided to implement no.1 as a lookup table (rather than enum or a hardcoded check).
About no.2 I figured the best way to enforce participation and exclusivity constraints on the four relationships would be a trigger.
The problem is that now I'm not really sure how to write a trigger function; for instance it would have to reference values inserted into business type, so I'd have to make sure those can't be changed or deleted in the future.
I feel like I'm doing something wrong so I wanted to ask for feedback before going further; is this a suitable approach in your opinion?
I found an interesting article describing a possible solution: it feels a bit like an 'hack' but it should be working
(it's intended for SQL Server, but it can be easily applied in postgres too).
EDIT:
It consists in adding a type field to the parent table, and then have every child table reference said field along with the parent's id by using a foreign key constraint (a UNIQUE constraint on this pair of fields has to be added beforehand, since FKs must be unique).
Now in order to force the type field to match the table it belongs to, one adds a check constraint/always generated value ensuring that the type column always has the same value
(eg: CHECK(Business_type_id = 1) in the Husbandry table, where 1 represents 'husbandry' in the type lookup table).
The only issue is that it requires a whole column in every subclass, each containing the same generated value repeated over and over (waste of space?), and it may fall apart as soon as the IDs in the lookup table are modified
I want to describe a self reference relation in a Liferay entity. Is there a recommended way to do this ?
I want to do this in order to describe a hierarchy.
At the moment, I just added a new column which I called "parentId" and I will save there the ID of the row that will be the parent of this one. If I use the "Diagram view", from within eclipse, if I draw a self reference relationship it adds a new row that duplicated the name of the ID: for example, suppose I want to describe an employee hierarchy - I have an Employee entity on which I add the default fields; one of these fields is the employeeId field which will be also the primary key. Now, if I draw a self reference relationship, the IDE will add another field entry that will be named the same way (eg. employeeId)
There is no official recommended way to do it, as you will have to add your own logic in your code to handle it.
In case you want to follow the convention used in Liferay code, Liferay code usually represents the hierarchy using a column called parent<primaryKey> and sometimes an auxiliary column called treePath to store the hierarchy path of the element, see:
https://github.com/search?q=repo%3Aliferay%2Fliferay-portal+filename%3Aservice.xml+parent&type=Code
https://github.com/search?q=repo%3Aliferay%2Fliferay-portal+filename%3Aservice.xml+treePath&type=Code
About the treePath column, service builder will add to the java class some methods (buildTreePath and updateTreePath) that will help to populate it, see the service builder templates: https://github.com/liferay/liferay-portal/blob/11e6081f96abb6bf299369519434c1eafa0658e3/modules/util/portal-tools-service-builder/src/main/resources/com/liferay/portal/tools/service/builder/dependencies/extended_model_base_impl.ftl#L65-L115
This column makes easier to get all the parent elements of the hierarchy, just split it by the / char and you will get all the primary keys of the ancestors.
The objective:
Having a many-to-many relation be displayed as a dynamic list of select inputs(single choice dropdown list)
User arrives on page with a single select field (multiple = false) populated with persisted entities and add/remove buttons. By clicking the add button, a new select field with the same options appears below the first, which adds a new entry in the M2M relation. By clicking remove the field disappears and the entry should be removed.
The model:
Two entities: User & Manager. A User has exactly one "special" Manager and unlimited normal Managers.
Managers manage unlimited users.To model this I have created two relationships for which the user is the "owner" (not sure how to translate this)
ManyToOne specialManager
ManyToMany normalManagers
I haven't created a many to many relationship with attribute "special" because the requirement is exactly one special manager and I wasn't sure if Symfony/Doctrine would cause problems down the line.
What I have:
I can display a multiple select field with the existing entities using Entity field type, as per the documentation. Functionally this is what I need, visually it is not.
I can also use the Collection field type to display a single text field, and add or remove more with JS, as per the documentation. Visually this is what I need, but The text fields (entity attribute) need to be replaced by choice field.
The question:
Before I continue digging, is there a simple way to achieve this list of select tags?
For anyone else who may eventually need a dynamic list of select fields:
I initially solved this issue by detaching the field(s) in event listeners, and handling the display/submission manually in the controller.
However I wasn't satisfied with this clunky solution and when I encountered the same need I used a second solution: creating an intermediary entity xxxChoice (in this case ManagerChoice) which is Mto1 inversed related to User and Mto1 related to Manager. Then by creating a ManagerChoiceType form with "Manager" entity field type I was able to easily display my collection of dropdown select lists.
Here is the senario for which I could not find anything useful. Maybe Im the first person thinking of doing it this way:
Approach: Database First
Database: SQL Server 2008 R2
Project : DLL (Data Access)
I have a data access library which encapsulates all the access to database as well as the biz functionality. The database has many tables and all the tables have the following 2 columns:
last_updated_on: smalldatetime
last_updated_by: nvarchar(50)
The project contains several models (or edmx files) which contain only related entities which are mapped to the tables they represent. Since each of the table contain the columns for last_updated_* I created a complex type in one of the models that is as follows:
Complex Type: History
By (string: last_updated_by)
On (DateTime: last_updated_on)
The problem is that it can only be used in the model in which I defined it.
A) If I try to use it in other model it does not show it in the designer
B) If i define it in the other models I get error History already defined
Is there any solution so that the History complex type, defined in one model can be reused by other models?
I was trying to do almost the exact same thing (my DB fields are "created", "creatorId", "modified", and "modifierId", wrapped up into a complex type RecordHistory) and ran into this question before finding an answer...
http://msdn.microsoft.com/en-us/data/jj680147#Mapping outlines the solution, but since it's fairly simple I'll cover the basics here too:
First create the complex type as you did (select the fields in the .edmx Designer, right click, select "Refactor into New Complex Type")
In the .edmx Designer (NOT the Model Browser) right click on another table/entity that has the same common columns and select Add -> Complex Property
The new property will be assigned a complex type automatically. If you have more than 1 complex type, edit the new property's properties and set the Type appropriately
Right-click on the table/entity again (in either the Model Browser or Designer) and select Table Mapping
Update the Value/Property column for each of your common fields (changing them, in my case, from "modified : DateTime" to "history.modified : DateTime")
Delete the old common fields from your entity, leaving just the complex type in their place
I have an entity model built using the designer. In one of my tables (application), I have several foreign keys that reference the same status (status) table. As a result, when my associations were built, I have several entity objects built with an auto indexing name:
application_statuses2
application_statuses3
etc.
I'm building a "version history" type screen and want to be able to properly list the "friendly name" for each column modified. For example, I want to display "Destination Status" will be displayed instead of "application_statuses2". If I can determine the endpoint column name on the association in question, I can setup the proper display value.
I can find the entity object in the designer, I can even track where it references the foreign key in question that built the association, but I can seem to find the property that outlines the enpoints or column names. How do I determine the column name, or endpoint, on my association, or entity?
I wish it were more ready to hand, have been looking for it as well. Bit of a pain when you have multiple FKs to the same table.
Click on the navigation property you want to check
Under properties, look at the name of the association
At the top of properties, use the object navigator dropdown to switch to the association
Click into the 'Referential Constraint' property
Use the ellipses button on the right to bring up the column names
Dont know if there is a better way of doing this, but I certainly hope so!