The detailed comparison on the E- R model and Object Oriented Model is given as follows −E-R ModelER model is used to represent real life scenarios as entities. The properties of these entities are their attributes in the ER diagram and their connections are shown in the form of relationships. An ... Read More

Class hierarchy can be viewed one of two waysSpecialization (Top Down Approach)Generalization (Bottom Up Approach)SpecializationSpecialization is a process of identifying subsets of an entity that shares different characteristics. It breaks an entity into multiple entities from higher level (super class) to lower level (subclass). The class vehicle can be specialized into ... Read More

Moving objects are those whose position changes frequently over a period of time. Conventional databases don't know how to handle this scenario, as they assume the data objects are stationaryIn this case, we use moving object databases. These databases can store information about moving objects and allow querying on them.For ... Read More

Conventional relational databases were the product of a great deal of research and testing to obtain optimal storage structures. However, their flaw is that they have a rigid structure which cannot be altered if there are different specifications. To combat this problem, NoSQL databases were created.There are many different types ... Read More

Mandatory and optional participation are observed in E-R models between 2 different entities.Mandatory ParticipationIn the mandatory participation, for every instance of entity A, there must exist an instance of entity B and vice versa.An example of Mandatory participation would be relationship between mother and child. The child entity would exist ... Read More

Many to Many relationship implies multiple relationship between any two entities. An example of this is: A class has multiple students but a student also attends multiple classes. So this is a many to many relationship between the entities STUDENT and CLASS.It is complicated to manage a many to many ... Read More

ER model is used to represent real life scenarios as entities. The properties of these entities are their attributes in the ER diagram and their connections are shown in the form of relationships.Some examples of ER model are −Hospital ER ModelThis is an ER model of a Hospital. The entities ... Read More

Use the flex-wrap class in Bootstrap 4 to wrap flex items. The following is the code snippet to wrap the flex items −   .   .  

To set an element to have rounded corner, use the rounded-bottom class in Bootstrap 4.Set the rounded-bottom class −In the above , I have also set another class for styling the element −.demo {   width: 100px;   height: 120px;   margin: 10px;   background-color: orange; }You can try to ... Read More

Use the align-baseline class in Bootstrap 4 to align an element with the baseline of the parent elment.Set the align-baselinec class like the following code snippet −Now add the content inside it −     Demo Baseline You can try to run the following code to align an element with ... Read More