HomeworkLib
Question

Put a table which may occur in the Relational DB version of your Entity-Relationship Diagram. What is an example of a key-constraint in this instance?

Example: example_col_4 example_col_1 entry_1 example_col_2 entry_2 example_col_3 entry_3 entry_4 Key-constraint: for a given

engineering   Computer-Science   
0 0
Add a comment Improve this question Transcribed image text
Next > < Previous
Sort answers by oldest

Homework Answers

Answer #1

******************************************************************************************
Please Upvote the answer as it matters to me a lot :)
*****************************************************************************************
As per HomeworkLib expert answering guidelines,Experts are supposed to answer only certain number of questions/sub-parts in a post.Please raise the remaining as a new question as per HomeworkLib guidelines.
******************************************************************************************

Student table

Student_id studentName contactNo department_id

1 Jonny 123 cs

1 papa 234 ec

NULL Sugar 858 it

key constraint: primary key must have unique values and cannot be null

0 0
Add a comment
Know the answer?
Add Answer to:
Put a table which may occur in the Relational DB version of your Entity-Relationship Diagram. What...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions

  • Please answer true or false 27) Relationship instances occur when an instance of one entity is...

    Please answer true or false 27) Relationship instances occur when an instance of one entity is related to an instance of another entity via a relationship. 28) Two columns of a relational table can have the same values. 29) If one of two identical relational tables has the first row moved to the last place, those two relational tables are no longer identical. 30) An entity and its 1:1 unary relationship are mapped as one relation. 31) An entity and...

  • DRAW THE ERD(CDM) AND GENERATE THE RELATIONAL TABLE (PDM) USING POWER DESIGNER. PLEASE COMPLETE EACH ENTITY...

    DRAW THE ERD(CDM) AND GENERATE THE RELATIONAL TABLE (PDM) USING POWER DESIGNER. PLEASE COMPLETE EACH ENTITY WITH ATTRIBUTES INCLUDING PRIMARY KEY AND FOREIGN KEY CONSTRAINTS PROBLEM 3 - Draw an entity-relationship diagram for the following scenario, stating any assumptions you find it necessary to make, and showing unknown cardinalities and optionalities using question marks on the relationship line. Show also the attributes explicitly mentioned in the scenario and underline any you consider suitable candidates for being primary keys. It is...

  • QUESTION 1 What is the most common relationship within a relational database? Select the best answer...

    QUESTION 1 What is the most common relationship within a relational database? Select the best answer from the following. One-To-One relationship. o One-To-Many relationship. Many-To-Many relationship. Zero-To-Zero relationship. QUESTION 2 What is an "entity'? Select the best answer from the following. An entity, for our purposes, is the same as a table in the database. An entity represents one of the columns in an individual table. There are no entities in a relational database. Entities are only part of NoSQL...

  • For this assignment, you should create an Entity Relationship Diagram (ERD) in Visio that shows a...

    For this assignment, you should create an Entity Relationship Diagram (ERD) in Visio that shows a many-to-many relationship between DeVry University students and their classes. Since one student can have many classes and each class can have many students, you will need to create an associative entity to store the specific Student_Class data such as grade and attendance. Create the tables as well as the relationships. Don't forget to indicate the Primary Key and Foreign Key in each table. Tables...

  • 37.          Entity-Relationship diagram is developed in _________________.                       &

    37.          Entity-Relationship diagram is developed in _________________.                                 A. Conceptual Data Model                                                                           B. Logistical Database Design                                 C. Physical Database Design                                                                         D. Implementation 38.          Which of the following database models only expresses a 1:M relationship?                                 A. Hierarchical model                                 B. Relational model                                 C. Objected-oriented model                                 D. Network model 39.          The subtype discriminator is a simple attribute when there is a(n):                                 A. overlap rule                                                                   B. disjoint rule                                 C. no specialization                                                          D. None of the above 40.         ...

  • Map this E-R Diagram to a Relational DBMS. Each table/relation represents one "entity type". The rows...

    Map this E-R Diagram to a Relational DBMS. Each table/relation represents one "entity type". The rows represent instances of that type of entity and the columns representing values attributed to that instance. Name Schedded DepTme City S白 DEPARTURE AIRPORT AIRPORT FLIGHT LEG ARRIMAL AIRPORT LAND LEGS NSTANCE Weekdays Max-seats Number Compary FLIGHT AIRPLANE TYPE ARRVES FARES Oode FARE Date №daal seats LEG INSTANCE AIRPLANE ASSIGNED CPhone NOTES (1ALEG (SEGMENT)ISANONSTOP PORTION OFAFLIGHT (2)ALEG INSTANCE ISAPARTICLLAROOCURRENCE RESERMATION OFALEG ON A PARTICULAR DATE...

  • This is symbolized by a circle over a single line in an entity relationship diagram. It...

    This is symbolized by a circle over a single line in an entity relationship diagram. It signifies that the supertype does NOT have to be one of the specified subtypes. Partial completeness Total completeness System completeness Associative completeness A supertype entity can contain as many as ____ subtype entities. 10 1 100 no defined limit When you set up an Entity Relationship Diagram, and have a many-to-many relationship, this entity is created to avoid problems inherent to a many-to-many relationship....

  • The following are the main entity types of the academic institution database. For each entity type,...

    The following are the main entity types of the academic institution database. For each entity type, we provide some of the corresponding attributes. Use this information in order to: (a) Build an Enhanced E-R diagram; (b) Transform the Enhanced E-R diagram to a relational database. Identify the primary key(s) and the foreign key(s) for each relation. Draw the relational integrality constraints; (c) For each of the relations created, indicate its normal form. If the relation is not in the 3NF,...

  • Create an Entity-Relationship Diagram (ERD). In the ERD include the following:

    Create an Entity-Relationship Diagram (ERD).In the ERD include the following: entities primary keys for all entities attributes - use "good" names for attributes, use only single-valued attributes relationships - use Crow's foot or UML notation; name relationships that could be ambiguous cardinality - minimum (optional/mandatory) and maximum (one or many) on both ends of the relationship - use reasonable assumptions if there is insufficient information in the descriptionStudent/Course registration system for a universityStudents have a unique identification number, first name, middle initial, last name, year...

  • Name Use complete sentences if possible The following StudentGrade relation (table) stores the Student, Major, and Course information Each student has unique StudentID. Assume that a student has...

    Name Use complete sentences if possible The following StudentGrade relation (table) stores the Student, Major, and Course information Each student has unique StudentID. Assume that a student has only one major. One student can take multiple courses in one SemesterYear. One course can be taken by many students in each SemesterYear. Given values for StudentID, Course Number, and SemesterYear, one can determine all the rest of values for a record. However only Grade is functionally dependent on StudentlD, CourseNumber and...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT