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3 years ago

What is a foreign key and how does it provide referential integrity?

Computers and Technology

1 answer:

Step2247 [10]3 years ago

4 0

Answer:

By definition a foreign key of table A is a primary key of another table B, thereby establishing a link between them.

To provide referential integrity you can use these referential actions:

<u>Cascade:</u> If rows in table B are deleted, the matching foreign key columns in table A are deleted.

<u>Set Null:</u> If rows in table B are deleted, the matching foreign key columns in table A are set to null.

<u>Set Default:</u> If rows in table B are deleted, the matching foreign key columns in table A are set with the default value of the column.

<u>Restrict:</u> A value in table B cannot be deleted or updated while as it is referred to by a foreign key in table A.

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kondaur [170]

Answer:

na bro, esta dificil

Explanation:

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3 years ago

Select the correct answer. Richard wants to use a technology that allows the automation of manufacturing cars in his factory. Wh

Gemiola [76]

CAM C. rapid prototyping is the correct option for Richard wants to use a technology that allows the automation of manufacturing cars in his factory.

<h3>What is prototyping?</h3>

Prototyping is an iterative process in which design teams translate abstract ideas into tangible forms, which might range from paper to digital.

To capture design concepts and test them on people, teams create prototypes of varied degrees of quality. one can modify and validate designs with prototypes.

Thus, option B is correct.

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2 years ago

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Write a C function which takes three parameters which are the cost for an item in a grocery store, the quantity to buy, and the

xeze [42]

Answer:

struct item

{

float previousCost;

float taxAmount;

float updatedCost;

} itemObject;

void calculation(int cost,int quantity,float tax)

{

struct item *itemPointer=&itemObject;

itemPointer->previousCost=(cost) * (quantity);

itemPointer->taxAmount=itemPointer->previousCost * (tax/100);

itemPointer->updatedCost=itemPointer->previousCost+itemPointer->taxAmount;

}

Explanation:

Define a structure called item that has 3 properties namely previousCost, taxAmount and updatedCost.
The calculation function takes in 3 parameters and inside the calculation function, make a pointer object of the item structure.
Calculate the previous cost by multiplying cost with quantity.
Calculate the tax amount by multiplying previous cost with (tax / 100).
Calculate the previous cost by adding previous cost with tax amount.

4 0

3 years ago

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1. Write a Python code to:

Ksenya-84 [330]

Answer:

hope this help and do consider giving brainliest

Explanation:

import numpy as np

A=np.array([[1,4,3,2],[1,7,4,5],[2,5,3,1],[1,3,2,9]]);

print("Inverse is");

B=np.linalg.inv(A);

print(B);

print("A*A^-1=");

print(np.dot(A,B));

print("A^-1*A=");

print(np.dot(B,A));

import numpy as np

A=np.array([[4,3,2],[5,6,3],[3,5,2]]);

B=np.array([[3,-1,2,6],[7,4,1,5],[5,2,4,1]]);

X=np.dot(np.linalg.inv(A),B);

print("X=");

print(X);

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3 years ago

What is the full form of PDA? HELP ME PLZ-

finlep [7]

Answer:

Patent ductus arteriosus (PDA)

Explanation:

Patent ductus arteriosus (PDA) is a medical condition in which the ductus arteriosus of a person fails to close after birth.

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2 years ago

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