Құрастырушы: Құрастырушылар: аға оқытушы Успанова А. И
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- Lecture 9. General notions protection to information
Reports. Now that you have all of your data stored in a database, you need to have a way to view it; this is where reports come in handy. 
Figure 36 - Report The strange thing is that you can go a long way in Access without explicitly working with Queries. In this lecture and also the labs, we are not dealing with Macros or VisualBasic. If you are interested, you are encouraged to read about that yourself. The labs can be done without both. In this lecture, we will create a database that implements the ER-diagram of Figure 40. 
Figure 37 – ER-diagram In very short words, we have students that participate in courses that are held by institutions. We need to implement the following tables (primary keys underlined, foreign keys in italics): 
You have the choice to create a new table using design view, a wizard or by entering data. The wizard is nice to test some times, it will suggest sample tables, but most often, especially when you have previous knowledge of database design, design view is more efficient. Table creation by entering data results in a table without column names and primary keys. Use design view. In design view, you enter column names, types, and other properties as textual data in a sheet as shown in Figure 41. 
Figure 38 – Design view Home task 
After this lesson, you should be able to write essay (about 250 words): - Development of tabular processor.
When the computer virus starts working, it is called the activation of virus. A virus normally runs all the time in the computer. Different viruses are activated in different ways. Many viruses are activated on a certain data. For example, a popular virus Friday, «the 13th» is activated only if the date is 13 and the day is Friday. According to Wikipedia «Computer viruses cause billions of dollars’ worth of economic damage each year, due to causing systems failure, wasting computer resources, corrupting data, increasing maintenance costs, etc». Computer virus cannot damage computer hardware. IT may cause many damages to a computer system. A virus can: A computer virus can damage data or software on the computer. It can delete some or all files on the computer system. It can destroy all the data by formatting hard drive. It may display a political or false message very few times. The following are the main causes of a Computer Virus. Infected Flash Drives or Disks. Flash drives and disks are the main cause of spreading viruses. Flash drives and disks are used to transfer data from one computer to other. A virus can also be copied from one computer to other when the user copies infected files using flash drives and disks. Email Attachments. Most of the viruses spread through emails. Email attachment is a file that is sent along with an email. An email may contain an infected file attachment. Virus can spread if the users opens and downloads an email attachment. It may harm the computer when it is activated. It may destroy files on the hard disk or may send the virus automatically to all email addresses saved in the address book. Infected entertainment websites. Thousands of insecure websites can infect computer with viruses. Most of the websites with entertainment materials are infected, so by visiting these websites the user’s computer also gets infected by virus. These websites are developed to spread viruses or other unethical material. The virus is transferred to the user’s computer when this material is downloaded. These websites may access the computer automatically when the users visit them. жүктеу/скачать 6,16 Mb. Достарыңызбен бөлісу:
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