
Concept explainers
Primary Key:
A Primary Key in a
Example:
Students in Universities are assigned a unique registration number. Therefore, in a STUDENT database table, the attribute “reg_no” acts as primary key.
Foreign Key:
Foreign Key is a column in a relational database table which provides a relation between two tables. It provides a cross reference between tables by pointing to primary key of another table.
Example:
In STUDENT database table, the attribute “reg_no” acts as primary key and in COURSE database table in which the student selects his or her course, the same “reg_no” acts as foreign key for the STUDENT table.
Given database tables:
Table Name: EMPLOYEE
EMP_CODE | EMP_TITLE | EMP_LNAME | EMP_FNAME | EMP_INITIAL | EMP_DOB | STORE_CODE |
1 | Mr. | Williamson | John | W | 21-May-84 | 3 |
2 | Ms. | Ratula | Nancy | 09-Feb-89 | 2 | |
3 | Ms. | Greenboro | Lottie | R | 02-Oct-81 | 4 |
4 | Mrs. | Rumpersfro | Jennie | S | 01-Jun-71 | 5 |
5 | Mr. | Smith | Robert | L | 23-Nov-59 | 3 |
6 | Mr. | Renselear | Cary | A | 25-Dec-85 | 1 |
7 | Mr. | Ogallo | Roberto | S | 31-Jul-82 | 3 |
8 | Ms. | Johnson | Elizabeth | I | 10-Sep-88 | 1 |
9 | Mr. | Eindsmar | Jack | W | 19-Apr-55 | 2 |
10 | Mrs. | Jones | Rose | R | 06-Mar-66 | 4 |
11 | Mr. | Broderick | Tom | 21-Oct-72 | 3 | |
12 | Mr. | Washington | Alan | Y | 08-Sept-74 | 2 |
13 | Mr. | Smith | Peter | N | 25-Aug-64 | 3 |
14 | Ms. | Smith | Sherry | H | 25-May-66 | 4 |
15 | Mr. | Olenko | Howard | U | 24-May-64 | 5 |
16 | Mr. | Archialo | Barry | V | 03-Sep-60 | 5 |
17 | Ms. | Grimaldo | Jeanine | K | 12-Nov-70 | 4 |
18 | Mr. | Rosenburg | Andrew | D | 24-Jan-71 | 4 |
19 | Mr. | Rosten | Peter | F | 03-Oct-68 | 4 |
20 | Mr. | Mckee | Robert | S | 06-Mar-70 | 1 |
21 | Ms. | Baumann | Jennifer | A | 11-Dec-74 | 3 |
Table Name: STORE
STORE_CODE | STORE_NAME | STORE_YTD_SALES | REGION_CODE | EMP_CODE |
1 | Access Junction | 1003455.76 | 2 | 8 |
2 | Database Corner | 1421987.39 | 2 | 12 |
3 | Tuple Charge | 986783.22 | 1 | 7 |
4 | Attribute Alley | 944568.56 | 2 | 3 |
5 | Primary Key Point | 2930098.45 | 1 | 15 |
Table Name: REGION
REGION_CODE | REGION_DESCRIPT |
1 | EAST |
2 | WEST |

Trending nowThis is a popular solution!

Chapter 3 Solutions
Bundle: Database Systems: Design, Implementation, & Management, 13th + Mindtap Mis, 1 Term (6 Months) Printed Access Card
- Draw an ERD that represents a book in a library system. Be sure to add relationship types, key attributes, attributes and multiplicity on the ERD.arrow_forward2:21 m Ο 21% AlmaNet WE ARE HIRING Experienced Freshers Salesforce Platform Developer APPLY NOW SEND YOUR CV: Email: hr.almanet@gmail.com Contact: +91 6264643660 Visit: www.almanet.in Locations: India, USA, UK, Vietnam (Remote & Hybrid Options Available)arrow_forwardProvide a detailed explanation of the architecture on the diagramarrow_forward
- hello please explain the architecture in the diagram below. thanks youarrow_forwardComplete the JavaScript function addPixels () to calculate the sum of pixelAmount and the given element's cssProperty value, and return the new "px" value. Ex: If helloElem's width is 150px, then calling addPixels (hello Elem, "width", 50) should return 150px + 50px = "200px". SHOW EXPECTED HTML JavaScript 1 function addPixels (element, cssProperty, pixelAmount) { 2 3 /* Your solution goes here *1 4 } 5 6 const helloElem = document.querySelector("# helloMessage"); 7 const newVal = addPixels (helloElem, "width", 50); 8 helloElem.style.setProperty("width", newVal); [arrow_forwardSolve in MATLABarrow_forward
- Hello please look at the attached picture. I need an detailed explanation of the architecturearrow_forwardInformation Security Risk and Vulnerability Assessment 1- Which TCP/IP protocol is used to convert the IP address to the Mac address? Explain 2-What popular switch feature allows you to create communication boundaries between systems connected to the switch3- what types of vulnerability directly related to the programmer of the software?4- Who ensures the entity implements appropriate security controls to protect an asset? Please do not use AI and add refrencearrow_forwardFind the voltage V0 across the 4K resistor using the mesh method or nodal analysis. Note: I have already simulated it and the value it should give is -1.714Varrow_forward
- Database Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781305627482Author:Carlos Coronel, Steven MorrisPublisher:Cengage LearningA Guide to SQLComputer ScienceISBN:9781111527273Author:Philip J. PrattPublisher:Course Technology Ptr
- Database Systems: Design, Implementation, & Manag...Computer ScienceISBN:9781285196145Author:Steven, Steven Morris, Carlos Coronel, Carlos, Coronel, Carlos; Morris, Carlos Coronel and Steven Morris, Carlos Coronel; Steven Morris, Steven Morris; Carlos CoronelPublisher:Cengage LearningNp Ms Office 365/Excel 2016 I NtermedComputer ScienceISBN:9781337508841Author:CareyPublisher:Cengage



