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What else can I help you with?
What is difference between object and entity?
A database object is represented as one of the following: database, schema, table, column, primary key, and foreign key A database Entity is: An entity is a thing or object of importance about which data must be captured. All things aren't entities - only those about which information should be captured. Information about an entity is captured in the form of attributes and/or relationships. If something is a candidate for being an entity and it has no attributes or relationships, it isn't an entity. Database entities appear in a data model as a box with a title. The title is the name of the entity.
What is weak entity sets in dbms?
An entity set may not have sufficient attributes to form a primary key is called weak entity set. One with primary key is called strong entity set.
What is peer entity?
In layered systems, one of a set of entities that are in the same layer or the equivalent layer of another system.
What do you understand by table relationship in database design?
A table relationship is where a field in one table is matched with the same field in another table. For example you may have a table that lists your suppliers so 'Supplier Name' is one of the fields, you may then have another table that lists orders made so "Supplier Name" will be a field in that table also. Therefore you can link the two tables together so that all specific supplier address details are linked to subsequent orders with that supplier. For a relationship to work both linking fields must be of the same data type, therefore you can't link a field that is stated as text with one that is stated as a date. Relationships are commonly known as one-to-one and one-to-many, in a one-to-one relationship the field's contents can only appear once on each side so using the example above one supplier in the suppliers table can only have one order record in the orders table. "One to many" therefore means that one supplier can appear on many orders. Hope this helps.
Entity relationship diagram of hr system?
In case you have no background in computer science, entity relationship is a method that conceptually identifies the interacting, and independent objects( both physical and otherwise) in an information system with the view to avoid data redundancy, maintain data integrity, improve data efficiency, increase resource utilization in terms of storage management and access speed or system response time. Pls let stop here. An instance of your diagram, which I will stress you little, is to quickly image 1. A hostel and rooms in it, here Hostel as well as the rooms are treated as different entities. 2. imagine manager and employee under him in an organization, even though they can all be referred to as employees yet manager is different entity In a nut shell we use a line to link two interacting entities and the cardinality( which is to be discuss professionally as either one to one, one to many). That is all. I am not too good at drawing but I could conceptualize it mentally. If this does not satisfy you do not hesitate to mail me at: maduchudi@yahoo.com I will always be for you all.
When do you have to use an intersection entity in database?
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.
What is a democratic relationship?
a democratic relationship is one that each person is participating equally....
What is democratic relationship?
a democratic relationship is one that each person is participating equally....
What is one to one relationship?
There are three types of relationship in a database . One to one, one to many and many to many , Example of many to many relationship is relation between teachers and students, n teachers can have m students.
What two conditions must be met before an entity can be classified as a weak entity?
In contrast to the strong or regular entity, a weak entity is one that meets two conditions: 1. The entity is existence-dependent; that is, it cannot exist without the entity with which it has a relationship. 2. The entity has a primary key that is partially or totally derived from the parent entity in the relationship.
Can an identifying relationship of a weak entity type will be of a degree greater than two give example?
Sure thing, honey. An identifying relationship of a weak entity type can definitely have a degree greater than two. For example, let's say we have a weak entity type called "Order Item" that depends on both "Order" and "Product" entities to uniquely identify it. In this case, the identifying relationship would have a degree of two (connecting "Order" and "Product") but the weak entity type itself would have a degree of three. Hope that clears things up for ya!
What is total participation in database management?
Participation (or optionality) concerns the involvement of entities i a relationship. Participation is about exceptions to the rule. An entity's participation is optional if there is a least one instance of an entity which does not participate in the relationship. An entity participation is mandatory if all instances of an entity must participate in the relationship.
What is a one-to-many relationship?
It is a term from computer databases. A relational database can have a one-to-many relationship in its data. For example, if you have a customer order database, one table will contain customer names and another will contain their orders. Each customer will only be listed once, but each customer can make many orders. So one customer can be related to many orders. Incorporating that into a database requires the creation of a one to many relationship.
What is One to one relationship in ERD?
Here is Example!! Entity: PERSON Att:Baby_Name, Father_Name Entity: CITY Att: Country_Name, City_Name, Hospital_Name 1 To 1 Relation: One Baby born at one place(Hospital).
Explain what cardinality constraints are and how they impact on database design?
A Cardinality Constraint is when a certain relation can only have a certain number of instances for a relationship. For example, a Voter can only vote once in an election. Thus, there needs to be a cardinality constraint on the relationship VotedIn that relates a Voter to Election.
1 A one-to-one binary relationship involves a single entity type?
I would love to answer your. . . sentence but it isn't a question. :) Sorry for your inconvenience.
What is cardinality in an ER diagram?
An E-R diagram may also indicate the cardinality of a relationship. Cardinality is the number of instances of one entity that can, or must, be associated with each instance of another entity. In general we may speak of one-to-one, one-to-many, or many-to-many relationships. There are several different styles used to draw Entity-Relationship diagrams. The Kendall and Kendall text uses the Crow's Foot notation. Using this notation entities are represented by rectanges and relationships are indicated by lines connecting the rectangles. Cardinality is shown by a series of "tick marks" and "crows feet" superimposed on the relationship lines.
