ER diagram is Entity Relationship Diagram which shows relationship between different entities in a process....
Data Flow diagram is a symbolic structure which shows the flow of data how it is
used in diff stages in a particular process....
Degree the number of entity types that participate in a relationship.
the difference between a reporting entity and a taxable entity is, a reporting entity is the company or organization and the taxable entity is the individual.
A relationship between instances of a single entity type is called a self-relationship or recursive relationship. This type of relationship occurs when an entity is related to other instances of the same entity type within the same entity set.
Entity - Table Entity Set - Rows in Table
If you have a many-to-many relationship between two entities you create an intermediate entity between.Now, the relationship between the first entity and intersection entity is one-to-many, and the relationship between the second entity and intersection entity is one-to-many also.
A relationship with attributes should be an associative entity when: - All relationships for the associative entity should be many - The associative entity could have meaning independent of the other entities - The associative entity should have attribute(s), but it may or may not have an identifier - The associative entity may participate in other relationships other than the entities of the associated relationship - Ternary relationships should be converted to associative entities
Martin Gogolla has written: 'An extended entity-relationship model' -- subject(s): Entity-relationship modeling, Prolog (Computer program language), SQL (Computer program language)
Entity-Relationship diagrams are useful for modelling data and the relationships between the data. They can be used when the constraints between data are relatively simple. They do not allow specification of interactions between the data or model how the data changes (there are no processes in Entity-Relationship). Entity-Relationship diagrams are most often used to model databases.
An entity relationship diagram for hotel reservation systems is a map of each entity or thing that has a part in the process of hotel reservations. The diagram maps the relationship between each entity of the process.
Program is a set of instruction whereas process is program in execution. Program is passive entity whereas process is active entity .Program has single instance whereas process has several instances.For eg.several notepad windows can be opened but same program is executed behind each window. Program is dependent on logic used whereas process is dependent on program.
Relation: In Database a relation represents a table or an entity that contain diffrenet attributes.An Entity constructs a relation(table) in DBMS . Relationship: In Data base relationship is that how the two entities are connected to each other ,i.e what kind of relationship type they hold between them.Primary/Foreign key is used to specify or hold this relationship. By Tanzeel Ur Rahman Bhatti
the difference between a proposer and the insured is that a proposer is a person or an entity who is seeking insurance and an insuerd is someone or an entity covered by an insurance policy