INVENTORIES 1 STORE M REQUEST M TRANSFER 2. For each of the entities identified‚ design tables and identify the possible candidate keys‚ the primary key‚ a probable foreign key‚ and potential secondary keys. a. PARTS (PART_NUMBER‚ STORE_NUMBER‚ PART_DESCRIPTION‚ QTY_ON_HAND‚ COST‚ RETAIL_PRICE) Candidate keys: PART_NUMBER is the only candidate key. No other field will identify parts uniquely. Primary key: PART_NUMBER is the primary key. Foreign key: STORE_NUMBER is a foreign
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FirstName‚ and Department as a key; these three attributes combined would insure that we would identify only one row. 2.13 Explain the difference between a primary key and a candidate key: Candidate keys are keys that uniquely identify each row in a relation. They can be single or composite. The primary key is the candidate key that is chosen as the key that the DBMS
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storage. (3) True or False? A business rule may be represented in an ER diagram using mandatory/optional symbols. (4) True or False? Duplicate tuples are allowed in a relation. (5) True or False? If there is only one candidate key for a relation‚ then the candidate key automatically becomes the primary key. (6) True or False? The primary key referenced by a foreign key must be in a different relation from the foreign key. (7) True or False? A RDBMS (relational database management
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the database. 5. What is work shadowing? * It means following and observing persons as they go through their work routine. 6. What is a candidate key? * A Candidate Key can be any column or a combination of columns that can qualify as unique key in database. There can be multiple Candidate Keys in one table. Each Candidate Key can qualify as Primary Key. 7. What is a composite key? * A key that consist of more than one attribute. 8. What is a natural key?
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describes the stored data in terms of the data model of the DBMS. In a relational DBMS‚ the conceptual schema describes all relations that are stored in the database Alternate key - An alternate key is any candidate key which is not selected to be the primary key Candidate key - A candidate key is a field or combination of fields that can act as a primary key field for that table to uniquely identify each record in that table. Primary key - a primary key is a value that can be used to identify
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columns of the two tables. Students (Student ID‚ firstName‚ lastName‚ Course ID) Courses (Course ID‚ CourseName) b) For each of the tables you created‚ what are the candidate keys? There are Students Table and Courses Table. Students Table: Candidate keys include student ID‚ firstName and lastName. Courses Table: They candidate key is the Course ID and courseName. c) For each of the tables you created‚ what is the primary key? The primary key of Students Table is Student ID. The primary
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functional dependency? Give an example of functional dependency. a functional dependency is a constraint between two sets of attributes in a relation from a database. PubID determines the pubName‚ City‚ State‚ and Country. 4. What is a primary key? A candidate key to uniquely identify other columns in the relation 5. What is a foreign key? A column or a set of columns whose values match the values of the primary key in another relation 6. Describe update anomalies by using an example. . Membership fees
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DATA: A collection of known facts and figures. May contain text‚ numbers‚ images‚ sounds or videos etc. It doesn’t convey useful information METADATA: Data about data (describes prop and char of other data) INFORMATION: 1. Processed form of data is called Information 2. Processed data to increase knowledge of user e.g Name‚ Ages Older than 30 * Bit: Smallest unit of data; binary digit (0‚1) * Byte: Group of bits that represents a single character * Field: Group of words
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Chap 1: A system is a set of steps (process) put together to accomplish a task. An information system (IS) is an arrangement of people‚ data‚ processes‚ and information technology that interact to collect‚ process‚ store‚ and provide as output the information needed to support an organization.Types of IS : A transaction processing system (TPS): captures and processes data about business transactions. A management information system (MIS): provides for management-oriented reporting based on other
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database the business problem it is designed to solve is called? Domain of the database. observing people at work to see how they interact with data is called. Work shadowing which of the following best describes an attribute that can be primary key? candidate key a key that consists of 2 or more attributes combined is called: Composite key which of the follow represents the advantage of natural key? a natural key belongs to and describes the attributes. what type of relationships are shown is 1-1
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