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Marianna [84]
2 years ago
6

Short notes on primary key​

Computers and Technology
1 answer:
Thepotemich [5.8K]2 years ago
5 0

Answer:

A primary key is a special relational database table column (or combination of columns) designated to uniquely identify each table record. A primary key is used as a unique identifier to quickly parse data within the table. A table cannot have more than one primary key.

Primary Key.

Candidate Key.

Alternate Key.

Super Key.

Composite Key.

Foreign Key.

Unique Key.

In the relational model of databases, a primary key is a specific choice of a minimal set of attributes that uniquely specify a tuple in a relation. Informally, a primary key is "which attributes identify a record," and in simple cases constitute a single attribute: a unique ID.

Explanation:

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Given a string variable s that has already been declared, write some code that repeatedly reads a value from standard input into
valina [46]

Answer:

The code to this question can be given as:

Code:

while ((s!="Y" && s!="y" && s!="N" && s!="n"))  //loop for check condition

{

cin >> s;  //insert value

}

Explanation:

The description of the following code:

  • In this code, we use a string variable s that has been to define in question.
  • In code, we use a while loop. It is an entry control loop in loop we check variable s value is not equal to "y", "Y", "n" and "N".  
  • In the loop we use AND operator that checks all value together. If this is true So, we insert value-form user input in string variable that is "s".
4 0
3 years ago
4. You are planning to buy a new couch for your family room. Before you leave for the furniture store, you measure the available
zysi [14]
First, convert feet to inches. The ' denotes foot measurement while the " denotes inches. Since there are 12 inches in a foot,

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c.) Since the couch is between the limits, yes it would fit the space.

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8 0
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Why backup system of data and software is necessary. ​
zavuch27 [327]

Answer:

The purpose of the backup is to create a copy of data that can be recovered in the event of a primary data failure. Primary data failures can be the result of hardware or software failure, data corruption, or a human-caused event, such as a malicious attack (virus or malware), or accidental deletion of data.

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What is a attack vector<br>​
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Answer: A vector in computing, specifically when talking about malicious code such as viruses or worms, is the method that this code uses to propagate itself or infect a computer. This sense is similar to, and derived from, its meaning in biology

Explanation:

give me a Brainliest

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