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

Algorithms, Data array A has data series from 1,000,000 to 1 with step size...

Data array A has data series from 1,000,000 to 1 with step size 1, which is in perfect decreasing order. Data array B has data series from 1 to 1,000,000, which is in random order.

Define sr flip flop - sr latch with nor gate, Define SR Flip Flop - SR latc...

Define SR Flip Flop - SR latch with NOR Gate? The SR Flip flop neither is a circuit with two cross-coupled NOR gates or two cross-coupled NAND gates. SR

What is small computer systems interface, Q. What is Small Computer Systems...

Q. What is Small Computer Systems Interface? The other well-liked way is to connect a disk drive to a PC by a SCSI interface. Common drive choice for high-end workstations or s

What is pli, What is PLI Programming  Language  Interface  (PLI)  of  V...

What is PLI Programming  Language  Interface  (PLI)  of  Verilog  HDL  is  a  mechanism  to  interface  Verilog programs  with  programs  written  in  C  language.  It also pro

What is function scope, What is Function scope Function scope: A labe...

What is Function scope Function scope: A label is the only part of identifier that has function scope. A label is declared implicitly by its use in a statement. Label names m

Determine the logic gate having input 0 and output 1, The output of a logic...

The output of a logic gate is 1 when all its inputs are at logic 0. The gate is either ? Ans. When all inputs of logic gate at logic 0 and output is 0. The gate is either a NOR

What is the need of a hybrid in telephone networks, What is the need of a h...

What is the need of a hybrid in telephone networks? Digital exchanges need receive and transmit signals upon separate two-wire circuits. It calls for two-wire to four-wire con

Perceptron training, Perceptron training: Here the weights are initial...

Perceptron training: Here the weights are initially assigned randomly and training examples are needed one after another to tweak the weights in the network. Means all the exa

Advantage of crc over simple checksum, Why can CRC detect more errors than ...

Why can CRC detect more errors than simple Checksum? There are two purposes a CRC can identify more errors than a simple Checksum. 1. Since an input bit is shifted by all th

C token, describe briefly about the c token with suitable example program

describe briefly about the c token with suitable example program

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