UML basics: The class diagram
bank,branch,customer,loan,account (Entity Relationship Diagram) Creately diagrams can be exported and added to Word, PPT (powerpoint), Excel, Visio or . Rails ERD - Generate Entity-Relationship Diagrams for Rails applications. Build Status Code Climate. Rails ERD is a gem that allows you to easily generate a. Exercises Problem Construct an ER diagram (including important attributes) the basic relationships among customers, checking accounts, savings accounts, loans, and the bank branches where various accounts and loans are taken out.
Drawing Entity Relationship Diagram in Visual Paradigm
Naming a new column Press Enter to confirm. Now, you can repeat step 2 and 3 to add more columns. When finished editing, press Esc to confirm. In Visual Paradigm you can model a set type with the steps below: Add a column into the entity.
Right click on the column and select Open Specification Select varchar to be the Type of column. Enter the definition statement in the User type field, in pattern SET 'a','b','c', Defining user type NOTE: The User type field is only available when the DBMS selected in database configuration supports the definition of user type.
Click OK to confirm. Note that the definition will also be effective in database and DDL exporting. Specifying primary key There are several ways you can take to specify a column as a primary key. Specifying a primary key Alternatively, right click on a column and select Include in Primary Key to set the column as primary key or include it as part of a composite key. Finally, you can also find and check the Include in Primary Key option in the Column Specification window.
I still have no liabilities. So you can see the snapshot at the beginning of the month, in equity. Snapshot at the end of the month, in equity. And so to go from one point to the other, to go from toI must have grown in equity by And that's what the income statement describes.
It describes it right over here. The change in equity, sometimes it's the change in returned earnings or just change in equity.
Now, there's one thing that you're probably confused by right now. It's like, well, how do we reconcile everything with the cash? And that reconciliation is going to be done on the cash flow statement. And I'll do that in the next video. In basic aggregation relationships, the lifecycle of a part class is independent from the whole class's lifecycle. For example, we can think of Car as a whole entity and Car Wheel as part of the overall Car. The wheel can be created weeks ahead of time, and it can sit in a warehouse before being placed on a car during assembly.
In this example, the Wheel class's instance clearly lives independently of the Car class's instance. However, there are times when the part class's lifecycle is not independent from that of the whole class — this is called composition aggregation.
Drawing Entity Relationship Diagram
Consider, for example, the relationship of a company to its departments. Both Company and Departments are modeled as classes, and a department cannot exist before a company exists.
Here the Department class's instance is dependent upon the existence of the Company class's instance. Let's explore basic aggregation and composition aggregation further.
Basic aggregation An association with an aggregation relationship indicates that one class is a part of another class. In an aggregation relationship, the child class instance can outlive its parent class. To represent an aggregation relationship, you draw a solid line from the parent class to the part class, and draw an unfilled diamond shape on the parent class's association end.
Figure 12 shows an example of an aggregation relationship between a Car and a Wheel. Example of an aggregation association View image at full size Composition aggregation The composition aggregation relationship is just another form of the aggregation relationship, but the child class's instance lifecycle is dependent on the parent class's instance lifecycle. In Figure 13, which shows a composition relationship between a Company class and a Department class, notice that the composition relationship is drawn like the aggregation relationship, but this time the diamond shape is filled.
Example of a composition relationship View image at full size In the relationship modeled in Figure 13, a Company class instance will always have at least one Department class instance. Another important feature of composition aggregation is that the part class can only be related to one instance of the parent class e.
Reflexive associations We have now discussed all the association types. As you may have noticed, all our examples have shown a relationship between two different classes.