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2_Concepts_of_DB_presentation_l2_v1.ppt
10.3.2.1 define data types of database fields
10.3.2.2 create a one-table database
10.3.2.3 create a multi-table database
10.3.2.4 create a form for data entry
10.3.2.5 create reports using extracted data
Database Management System (DBMS) - software for creating databases, storing and searching the necessary information in them.
Microsoft Access data types
Text is a data type used to store plain, unformatted text of limited size (up to 255 characters).
Memo field is a special data type for storing large amounts of text (up to 65,535 characters).
Physically, the text is not stored in the field. It is stored in a different place in the database, and a pointer to it is stored in the field, but for the user such separation is not always noticeable.
Numeric - data type for storing real numbers.
Date / Time - type of data for storing calendar dates and current time.
Microsoft Access data types
Money - data type for storing monetary amounts.
Theoretically, it would be possible to use numeric type fields to write them, but for monetary amounts there are some features (for example, related to rounding rules) that make it more convenient to use a special data type, rather than setting a numeric type.
Counter - a special data type for unique (not repeated in the field) natural numbers with automatic extension.
Natural use - for ordinal numbering of records.
Boolean - a type for storing logical data (they can take only two values, for example, Yes or No).
Microsoft Access data types
The OLE object field is a special data type for storing objects, such as multimedia, inserted by embedding or linking (OLE).
Actually, of course, such objects are not stored in the table. As in the case of MEMO fields, they are stored elsewhere in the internal structure of the database file, and only pointers to them are stored in the table (otherwise working with tables would be extremely slow).
Hyperlink is a special field for storing the URL addresses of Internet Web objects. Clicking on the link automatically launches the browser and plays the object in its window.
The Lookup Wizard is not a special data type. This is an object, by setting which you can automate the entry in the data field so as not to enter them manually, but choose from the drop-down list.
Creating a database
File menu - Create
Specify the name of the created database
Creating a database table structure
In the database window, select the Table object.
Select the item Create a table in design mode
In the design window, specify the field name and data type
Determine the primary key of the table
Creating a database table structure
Establishing relationships between tables
Service Menu - Data Scheme
Add tables involved in relationships and close the Add window
Tow the Student table field to the appropriate field in the Books table.
Establishing relationships between tables
Activate the box Ensure data integrity and specify the type of relationship (one-to-many) and click the Create button.
Links are represented as lines between connecting fields of tables.
Creating forms for data entry in tables
Select Shape object
Select item Create form using wizard
Select table as the data source
From the list of available fields select the required fields.
Select the appearance of the forms of the proposed
Choose a design style
Enter the form name
Entering and editing data in tables using forms
Select a Form object
Open form
Fill in the appropriate form fields
Processing database information
You can process database information:
Using queries
In the process of performing a specially developed program
Query - instructions for the selection of records
Queries are of the following types:
Query query — to select data that is stored in tables and that does not change these tables.
Request-change - to change or move data:
To add entries
To delete records
To create a table
On update
Query with a parameter - determines the condition of the selection during the execution of the query
Processing database information
Database creation.
"Phonebook"
Имя поля | Тип поля |
The structure of one-table database (DB)
КОД
ФАМИЛИЯ
ИМЯ
ДАТА РОЖДЕНИЯ
НОМЕР ТЕЛЕФОНА
Числовой
Текстовый
Текстовый
Дата
Числовой
Practical work 1
Task 1. Create a report and a form of an already created database (Practical work 1).
Task 2. Create an algorithm for creating reports and forms.
Time to complete - 10 minutes
Reflection
Wish tree
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