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3 years ago

Which statements are true about a database?

Computers and Technology

2 answers:

anzhelika [568]3 years ago

6 0

Answer:

you cannot leave a field empty

you can enter data based on the defined data type

OverLord2011 [107]3 years ago

5 0

Answer:

You can enter data based on the defined data type.

A primary key uniquely identifies a record.

Explanation:

In a database, you can only enter data that matches the data type you have specified for that field. Therefore, you can enter text in fields with the text data type; numbers in fields with the number data type; or images in fields with the BLOb data type. You can have fields where data entry is optional. A primary key eliminates the chance of duplicate entries of the same record in a table.

You might be interested in

Design a database suitable for a university registrar. This database should include information about students, departments, pro

zalisa [80]

Answer:

For designing a database suitable for a University registrar, the following information is included which are Information about Students, Information about Departments, Information about Professors, Information about courses, Student Grades,TA's for a course, Department offering different courses.

In creating the database registrar system the following values are defined such as Entity, Attributes of entities,The relationship among entities.

Explanation:

Solution

The following requirements are for designing of database for a University registrar.

The Database Schema includes the following:

Information about Students
Information about Departments.
Information about Professors.
Information about courses.
Student Grades.
TA's for a course.
Department offering different courses.

Now,

For the design of Database for Registrar System we need to define the following:

(1)Entity: Student, Course, Instructor, Course offering.

(2) Attributes of Entities:

Student entity has Sid, name, program as its attributes
Course has Course_n, title, credits, and syllabus as its attributes
Instructor has iid ,name ,dept, title as its attributes
Course offering has section_no ,time, room, year,semester as its attributes

(3) Relationship among various entities:

Enrolls
Teaches
© is offered

Note: kindly find an attached copy of the E-R Diagram for University Registrar below, and his diagram shows student entity enrolls various courses which can be having teaches relationship with instructor. Course is being offered by relationship is offered by course offering.

5 0

3 years ago

Which of these completes the sentence? People interpret information ___________. Choose one.

evablogger [386]

Explanation:

mannejaondpsbma0jdjdhdj

5 0

3 years ago

Read 2 more answers

Subtract (100000)2 from (111)2 using 1s and 2s complement method of subtraction

GenaCL600 [577]

Answer:

-11001

Explanation:

The following steps are performed in order to perform subtraction of the given binary numbers:

Step 1:

Find 2’s complement of the subtrahend. The subtrahend here is 100000

100000

First take 1's complement of 100000

1's complement is taken by inverting 100000

1's complement of 100000 = 011111

Now takes 2's complement by adding 1 to the result of 1's complement:

011111 + 1 = 100000

2's complement of 100000 = 100000

Step 2:

Add the 2's complement of the subtrahend to the minuend.

The number of bits in the minuend is less than that of subtrahend. Make the number of bits in the minuend equal to that of subtrahend by placing 0s in before minuend. So the minuend 111 becomes:

000111

Now add the 2's complement of 100000 to 000111

0 0 0 1 1 1

1 0 0 1 1 1

The result of the addition is :

1 0 0 1 1 1

Step 3:

Since there is no carry over the next step is to take 2's complement of the sum and place negative sign with the result as the result is negative.

sum = 1 0 0 1 1 1

2's complement of sum:

First take 1's complement of 1 0 0 1 1 1

1's complement is taken by inverting 1 0 0 1 1 1

1's complement of 1 0 0 1 1 1 = 0 1 1 0 0 0

Now takes 2's complement by adding 1 to the result of 1's complement:

0 1 1 0 0 0 + 1 = 0 1 1 0 0 1

Now place the minus sign with the result of 2's complement:

- 0 1 1 0 0 1

Hence the subtraction of two binary numbers (100000)₂ and (111)₂ is

(-011001)₂

This can also be written as:

(-11001)₂

6 0

3 years ago

How do you use the Internet? Think about your typical day. When are you using the Internet? For what purposes? What role does it

gladu [14]

Answer:

I would say something like this:

I use the internet mainly for communication, school and all the necessary informations. It has become a routine thing for every person on the planet. People are able to progress in almost all spheres of life. It can link people from all over and create communities.

5 0

4 years ago

In this problem, we want to compare the computational performance of symmetric and asymmetric algorithms. Assume a fast public-k

MariettaO [177]

Answer:

The AES decryption time is 8 minutes

Explanation:

GIVEN THAT:

The 1 GByte is equal to 230 bytes and equal to 233 bits

The RSA decryption time is calculated as = 233 / (100*230 )

= 83886. 06 seconds

= 23 hours

The RSA decryption time is 23 hours

The AES decryption time is calculated as = 233 / (17 * 230 )

= 481.81 seconds

= 8 minutes .

The AES decryption time is 8 minutes

4 0

4 years ago