True, you should avoid using power point notes always
Answer:
b. foreign key
Explanation:
In the database world, a foreign key is a field on one table and a primary key for another table. The purpose of a foreign key is to provide linkages between two or more tables. Given two tables A and B, and making A the point of reference, a primary key is a field that is unique in A while a foreign key is unique in B.
On another hand, a composite primary key is a combination of two or more fields/columns on database table that can be used to uniquely identify each row in the table.
In the database lingua, what we have is a unique key not a distinct key, though the two words are similar in meaning.
A duplicate key is used when an information may be repeatedly entered on a table.
So the correct option is a foreign key.
There isn't enough info for me to answer this with complete confidence XD.
in cloud storage we can save data online
Answer:
1 void parseEmailAddress(string email, string& username, string& domain)
2 {
3 int found = email.find("@")
4 if (found > 0)
5 {
6 username = email.substr(0, found);
7 domain = email.substr(found+1, -1);
8 }
9 return;
10}
Explanation line by line:
- We define our function.
- We use an open curly bracket to tell the program that we are starting to write the function down.
- We apply the find method to the email variable that was passed by the main program. The find method tells us where is the "@" located within the email.
- We use an if statement to ensure that the value that we found is positive (The value is negative if an only if "@" is not in the email address).
- We use an open curly bracket to tell the program that we are starting to write inside the if statement.
- We apply the substr method to the email to take the username; it receives a start and an end value, this allows us to take from the beginning of the email (position 0) until the "@".
- We apply the substr method to the email to take the domain; it receives the position of the "@" character plus one to take the first letter after the "@" and a minus-one representing the last character on the email.
- We use a closing curly bracket to tell the program that the if statement has finished.
- We return nothing because we are using reference parameters, which means that the memory positions of username and domain are going to be filled by our parseEmailAddress function and the main function can access those values directly.
- We use a closing curly bracket to tell the program that the function has finished.
