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CHAPTER 3: Entity-Relationship (E-R) Model and Normalization, Picture1 …

- - - - An update anomaly is a data incosistency that results from data redundancy and a partial update.
        
        An update anomaly. Emplyee 519 is shown as having different addreses on different records.
        -Nursyafiqa Tasya-
    - - A deletion anomaly is the unintended loss of data due to deletion of other data
        
        A deletion anomaly.All information about Dr. Giddens is lost when he temporarily ceases to be assigned to any courses.
        -Alisya-
    - - An insertion anomaly is the inabilty to add data to the database due to absence of their data.
        
        An insertion anomaly. Untill the new faculty member,Dr newsome, is assigned to teach at least one course, his details cannot be recorded.
        -Nursyafiqa Tasya-
  - - - NORMALIZATION PROCESS
      - BRIANNE MITH
        
        FIRST NORMAL FORM
        -No multi-valued attributes
        -Every attribute value is atomic
        -A relation is said to be 1 NF
        -AHMAD FAIQ-
        
        REPEATING GROUP
        Domain and Values
        
        suppose a novice designer wishes to record the names and telephone number of customers. He defines a customer table which looks like this:
        
        - Brendon Tini-
        
        The designer then becomes aware of requirement to record multiple telephone numbers for some customers. He reasons that the simplest way of doing this is to allow the "Telephone Number" field in any given record to contain more than one value.
        
        1 more item...
  - - - ~SARRAH AQILAH~
        
        example
        
        To convert to 2NF, we must remove partial dependency.
        
        We can do this by creating three tables:
        
        student (studId, StudName, Tel, Major)
        
        Course (CourseId, Course Title, Teacher, TeacherRoom)
        
        StudentGrade(StudId, CourseId, Grade)
        
        ERITNEY MAJA
        
        ERITNEY MAJA
    - - nursyuhadda ain
        
        Third Normal Form Table
        
        -Marcella-
        
        Before Third Normal Form Table
        
        -Marcella-
- - - - Example of Crow Foot
        Sabrynna.
        
        Entity:Examples & Category Sabrynna.
      - syahema naziera
        
        syahema naziera
      - Example of ER Model : CHEN
        
        -Nursyafiqah-
        
        Basic Elements of E-R Model
        ENTITY - An entity is a person, a place, an object, an event or a concept in the user environment about which the organization wishes to maintain data.
        -An entity has a noun name
        ATTRIBUTE - A description or an entity characteristic is known as attribute
        
        Used to differentiate object in an entity
        RELATIONSHIP -Relationship is the link between entities
        -Label = verb/conjuction
        -Nursyafiqah-
- - - - -Anastasia Jyntang-
        
        Relationship
        
        For each 1:1 binary relationship between Entity E1 and E2 in the logical data model, a copy of a primary key for entity E1(parent) will be placed in entity E2 (child) to represent the foreign key.
        
        The determination for parent entity and child entity depends on the relationship participation between the entities involved.
        
        The entity with optional relationship participation is categorized as the parent entity, and the entity with mandatory relationship participation is categorized as child entity.
        
        florence
        
        florence
        
        Whereas the Department has mandatory participation in the relationship Manage. Department must be managed by Worker. Because of this, the primary key attribute of the Worker entity is copied into the Department entity as foreign key.
        
        However, if the involvement of both entities in the 1:1 relationship is optional or mandatory, the determination of parent entity is the most frequently accessed or queried by users.
        
        florence
- - - - PUTERI