Question :
What is cardinality in data modeling?
Subject
Software Engineering
Standard
Computer Science Engineering
Views
771
Asked By
Knowledge
Anaisha
Answer / Solution
Answer / Solution
In data modeling, cardinality refers to the relationship between two entities. There are three types of cardinality:
- One-to-one: Each row in the first table can be related to only one row in the second table. For example, a table of employees might have a one-to-one relationship with a table of employee salaries. Each employee would have only one salary, and each salary would be associated with only one employee.
- One-to-many: Each row in the first table can be related to zero or more rows in the second table. For example, a table of products might have a one-to-many relationship with a table of orders. Each product can be ordered multiple times, but each order will only have one product.
- Many-to-many: Each row in the first table can be related to zero or more rows in the second table, and vice versa. For example, a table of students might have a many-to-many relationship with a table of courses. Each student can take multiple courses, and each course can be taken by multiple students.
Cardinality is important for data modeling because it helps to ensure that the data in the database is consistent. For example, if a table has a one-to-one relationship with another table, then it is not possible for a row in the first table to be related to more than one row in the second table. This helps to ensure that the data in the database is accurate and reliable.
Cardinality can be represented visually using entity-relationship diagrams (ERDs). An ERD is a graphical representation of a database schema. In an ERD, cardinality is represented by a line connecting two entities. The type of cardinality is indicated by the shape of the end of the line. For example, a one-to-one relationship is represented by a line with a diamond at one end. A one-to-many relationship is represented by a line with a crow's foot at one end. A many-to-many relationship is represented by a line with two crow's feet.
Cardinality is an important concept in data modeling. It helps to ensure that the data in the database is consistent and accurate. By understanding cardinality, you can create better data models that will support your business needs.
Top Trending Questions
- 9284 Views Thomson’s model of an atom, explain how the atom is neutral as a whole.
- 5285 Views What are the main characteristics of peer to peer systems?
- 4825 Views Draw a plot of α-particle scattering by a thin foil of gold to show the variation of the number of the scattered particles with scattering angle.
- 3842 Views Difference between Synchronous and Asynchronous Transmission
- 3651 Views Explain protocols in details.
- 3624 Views Explain advantages and disadvantages of mobile computing.
- 3453 Views Differentiate between homogeneous and heterogeneous mixtures with examples
- 3238 Views Define olfactory indicators. Name two subtances which can be used as olfactory indicator
- 3208 Views Properties of the Real Number System
- 3072 Views The first term of an AP is 5, the last term is 45 and the sum is 400. Find the number of terms and the common difference.
- 2914 Views What is the difference between interactive mode and script mode in Python?
- 2868 Views What are canal rays? Why anode rays are called canal rays. Mention two postulates of J.J. Thomsons Model
- 2860 Views Different Data Mining Tools in details
- 2842 Views Write advantages and disadvantages of Hierarchical Data Model
- 2787 Views Explain various Access Modifiers in Java
- 2756 Views How do you download files using ftp?
- 2724 Views What type of information is provided by MIS and DSS?
- 2685 Views Adaptability and adaption in mobile computing.
- 2668 Views What is animation? How are animated video clips generated? Also, What are the applications of computer graphics?
- 2664 Views What is ftp? How do you use ftp?
- 2658 Views What do you mean by data archiving?
- 2647 Views What is a text-to-speech system? What are its applications?
- 2630 Views What Is data mining? What is the role of data archiving in data mining?
- 2616 Views What is a mainframe? What are the good and bad characteristics of a mainframe?
- 2616 Views What type of creative works are given copyright? What is the period of a copyright?
- 2615 Views What is a recordable CDROM? How does it work?
- 2595 Views Ramkali saved Rs 5 in the first week of a year and then increased her weekly saving by Rs 1.75. If in the nth week, fher weekly savings become Rs 20.75, find n.
- 2577 Views Where is the Sahara desert located?
- 2573 Views Explain the design steps of the transform mapping.
- 2547 Views What is speech recognition? What are its applications?
- 2531 Views What do you understand by aerodynamically floating head?
- 2452 Views What is voice mail? What are the advantages and disadvantages of voice mail?
- 2451 Views Explain different types of Data Mining Techniques.
- 2443 Views What is the basic difference between transaction processing system and MIS?
- 2433 Views Write the distribution of electrons in carbon and sodium atoms
- 2430 Views What is the difference between transaction processing and on-line transaction processing
- 2396 Views What Are the Different Types of Machine Learning?
- 2387 Views Necessary conditions for autotrophic nutrition
- 2364 Views What is a DVDROM? What is its typical capacity?
- 2362 Views Write first four terms of the A.P. when the first term a and the common difference d are given as follows
- 2329 Views How do you ensure information integrity?
- 2316 Views Naresh earns 30800 per month. He keeps 50% for household expenses. what he save per month
- 2316 Views 60 percent of the students in a school are girls, If the total number of girls in the school is 690
- 2292 Views When will you say a body is in Uniform acceleration and non-uniform acceleration?
- 2288 Views Explain Atomic number, Mass number, Isotopes and Isobars with some examples. Also give any two uses of isotopes.
- 2288 Views A sum of Rs 700 is to be used to give seven cash prizes to students of a school for their overall academic performance. If each prize is Rs 20 less than its preceding prize, find the value of each of the prizes.
- 2280 Views How are water and minerals transported in plants?
- 2272 Views What does an Electrical Circuit Mean, Electrical Current and its units.
- 2253 Views What is telnet? How is it used?
- 2228 Views What is SRS? Why is it important? How does one arrive at a SRS?
- 2227 Views The houses of a row are numbered consecutively from 1 to 49. Show that there is a value of x such that the sum of the numbers of the houses preceding the house numbered x is equal to the sum of the numbers of the houses following it. Find this value of x. [Hint : Sx-1 = S49 – Sx ]
- 2217 Views What are the factors which influence the adsorption of a gas on a solid?
- 2209 Views What is feasibility analysis? How is it used?
- 2205 Views Write a note on civilizing mission of the colonisers and Huynh Phu So
- 2203 Views Which term of the AP: 21, 18, 15, . . . is – 81? Also, is any term 0? Give reason for your answer.
- 2190 Views Explain the inference rules for functional dependencies in DBMS
- 2180 Views Calculate the molecular masses of the following elements, Hydrogen, Oxygen, Chlorine, Carbon Di Oxide
- 2164 Views 1500 families with two children are selected randomly according to the data given. Compute the probability of a family, chosen
- 2158 Views Why did James Mill and Thomas Macaulay think that European education was essential in India?
- 2156 Views What are the activities carried out during system implementation phase?
- 2155 Views What is the role of desorption in the process of catalysis?
- 2151 Views What is rational number
- 2137 Views Define parallel connection and series connection?
- 2133 Views Explain in detail about Tableau in data visualization?
- 2123 Views Nested Loops in C
- 2105 Views What are the different parts of a URL? Explain the purpose of each part
- 2104 Views Explain how data mining may be used by a State Road Transport Corporation
- 2095 Views How will you find the valency of chlorine, sulphur and magnesium?
- 2080 Views What’s the difference between a generative and discriminative model?
- 2079 Views Class 8 Quiz MCQ Basic Questions
- 2078 Views The sum of the third and the seventh terms of an AP is 6 and their product is 8. Find the sum of the first sixteen terms of the AP.
- 2070 Views What rights does copyright give to the owner of the copyright?
- 2058 Views Describe the ideas behind the Tonkin Free School. To what extent was it a typical example of colonial ideas in Vietnam.
- 2050 Views What are polyatomic ions? Give examples?
- 2031 Views A long solenoid with 15 turns per cm has a small loop of area 2 cubic cm placed inside the solenoid to its axis.
- 2009 Views looping structure in python
- 1989 Views Which gas is usually liberated when an acid reacts with a metal?
- 1989 Views What is meant by Intellectual Property Rights (IPRs)?
- 1980 Views In a cricket match, a batsman hits a boundary 6 times out of 30 balls she plays. Find the probability that she did not hit a boundary.
- 1965 Views Connect python to mysql database
- 1960 Views What is open source software? List some open source software.
- 1943 Views 2 cubes each of volume 64 cm3 are joined end to end. Find the surface area of the resulting cuboids.
- 1935 Views Difference between Artificial intelligence and Machine learning
- 1917 Views How is our atmosphere different from the atmospheres on Venus and Mars?
- 1912 Views What is system evaluation? Why is it required?
- 1886 Views What is the syntax of Java Inheritance? Explain with example.
- 1867 Views Distinguish between speed and velocity.
- 1858 Views What is data Mining.
- 1853 Views If the sum of the first n terms of an AP is 4n − n2, what is the first term (that is S1)? What is the sum of first two terms?
- 1833 Views What is a Trojan? In what way is it different from a virus? How do you remove a Trojan from your PC?
- 1832 Views Explain why, when a motorcar makes a sharp turn at a high speed, we tend to get thrown to one side.
- 1822 Views What is Internet telephony? In what way is it different from Internet radio?
- 1807 Views What is a mobile computing?
- 1797 Views What is Internet radio? What are the advantages and disadvantages of Internet radio.
- 1744 Views Distinguish between the meaning of the terms adsorption and absorption. Give one example of each.
-
1736 Views
Check whether the following is quadratic equation:
(x + 1)2 = 2(x – 3) - 1728 Views How soil is formed?
- 1716 Views What is Inheritance in Java? Explain.
- 1703 Views feature of mobile computing
- 1698 Views Why did a major protest erupt in 1926 in the Saigon Native Girls School in Vietnam ? Explain.
- 1696 Views What is a computer virus? How does it infect computer systems?
- 1692 Views What is vector graphics? Where are vector graphics used?
- 1676 Views To counter the Chinese influence what steps did the French take in the sphere of education?
- 1676 Views Achievements of the Hindustan socialist Republican Association
- 1668 Views How do you know that your PC has been infected by a virus? If it is infected. how do you remove the infection?
- 1664 Views What is the difference between MIS and DSS?
- 1660 Views The sum of 4th and 8th terms of an A.P. is 24 and the sum of the 6th and 10th terms is 44. Find the first three terms of the A.P.
- 1659 Views What is plagiarism? Is copyright violation a criminal offence?
- 1651 Views Types of data in mobile computing
- 1632 Views What is a thin client? Why are thin clients preferred in certain applications?
- 1627 Views What are the three types of intellectual property? What kind of rights does IPR on computer software normally give?
- 1619 Views Give an example of client-server computing
- 1593 Views Shweta obtained 18 marks in a test of 25 marks. What was her percentage of marks
- 1589 Views What are the various elements of data design?
- 1588 Views What is mathematics
- 1586 Views Data Mining History
- 1582 Views Two spherical bobs, one metallic and the other of glass, of the same size are allowed to fall freely from the same height above the ground
- 1579 Views What is data security? What is the difference between data privacy and security?
- 1574 Views How do you ensure security of your database?
- 1571 Views What is information integrity? How is it different from data security?
