What are primary keys and foreign keys, Computer Engineering

Assignment Help:

What are primary keys and foreign keys?

Primary keys are the unique identifiers for every row. They must have unique values and cannot be null. Due to their significance in relational databases, Primary keys are the most fundamental of all keys and constraints. A table can have only one Primary key. Foreign keys are both a method of ensuring data integrity and a manifestation of the relationship among tables.

 


Related Discussions:- What are primary keys and foreign keys

Explain the violating basic security principles, Explain the violating basi...

Explain the violating basic security principles There are drawbacks to permitting users to access the Intranet as well as not permitting them. A simple consideration such as a

Illustrate the table of types of serach engines, Illustrate the table of ty...

Illustrate the table of types of serach engines Type in: CIE and the search engine would return about 22 million hits Type in

Failures, FAILURES Since reliability engineering is focused on the surv...

FAILURES Since reliability engineering is focused on the survivability or absence of failures, it is more concerned about failures,  understanding  their causes and defining re

What is associative mapping cache, Q. What is Associative Mapping Cache? ...

Q. What is Associative Mapping Cache? The most fastest and flexible cache organization employs an associative memory that is displayed in Figure below. The associative memory s

Explain the parallel data storage - application of flip flop, Explain the P...

Explain the Parallel Data Storage - application of flip flops? In digital systems, data are usually stored in groups of bits that represent numbers, codes, or other information

Explain three-way handshake mechanism, Explain Three-Way Handshake Mechanis...

Explain Three-Way Handshake Mechanism used by TCP to terminate a Session reliably. Just to guarantee that connection is sets up or terminated reliably, transfer control protoco

Prototyping and incremental development, a) Write  the main differences amo...

a) Write  the main differences among prototyping and incremental development.    b) Explain the commonality and main differences among agile approach and RUP.

#titlesoftware interface.., draw circuit diagram and the truth table that r...

draw circuit diagram and the truth table that represent demultiplexer

Explain the pdca cycle, Explain the PDCA cycle. PDCA is a four step pro...

Explain the PDCA cycle. PDCA is a four step problem solving method. The following are the description of each step: 1. P - Plan (Devise your Plan). Identify an opportunity a

What do you mean by true complement method, Q. What do you mean by True Com...

Q. What do you mean by True Complement Method? Explain in detail. Q. Show IEEE format for (12.75)10. Q. What are the various ways to represent Negative Numbers in computer sy

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd