☰ Contents · Computing

Database design and MS Access elements

Lessons 22–23 · 2 lessons · N. I. Taylaqov (general editor), A. B. Akhmedov, M. D. Pardayeva, A. A. Abdug‘aniyev, U. M. Mirsanov. Informatics and Information Technologies, Grade 10, 1st edition. “Extremum-Press”, Tashkent, 2017
23

Main elements of MS Access and field properties

Textbook: pp. 48–51
GoalGets to know the Access window, the object types and the field types; chooses a suitable type and size for each field.
New words
Navigation Pane: the panel at the left that lists the database objects · Navigation Panequery: a stored question that selects or calculates data from tables · so‘rovform: a window for entering and viewing records · formaAutoNumber: a field type whose value grows by itself with each new record · AutoNumber
Explanation

Access is part of the Microsoft 365 and Office suites for Windows; a free alternative is LibreOffice Base. It is started with a desktop shortcut, the Start menu or search. The ribbon tabs are: File (file operations for the database), Home, Create (create a table, query, form, report), External Data (import and export), Database Tools (linking tables and other tools). In the Navigation Pane on the left the object types are: Tables (store the data), Queries (select and calculate), Forms (enter and view), Reports (print), Macros (automate actions), Modules (program code). The “Pages” (web pages) of the old versions of Access no longer exist. The field types are: Short Text (up to 255 characters; the old name is Text), Long Text (long text; the old name is Memo), Number (Byte 0…255, Integer –32 768…32 767, Long Integer about ±2.1 billion, Single and Double – for fractions), Date/Time (years 100…9999), Currency (up to 15 digits in the whole part and 4 in the fraction), AutoNumber, Yes/No, OLE Object, Hyperlink and Attachment (attach a file). The database file has the extension .accdb.

Worked examples
Types for a students table: StudentID – AutoNumber; FullName – Short Text; BirthDate – Date/Time; Score (0…100) – Number, size Byte; Fee – Currency; Active – Yes/No; Notes – Long Text; Photo – Attachment; Site – Hyperlink.
Objects: the “Students” table stores the data; the “Best scores” query selects the scores above 90; the “Entry” form shows one student at a time; the “List” report prepares a class sheet for printing. Together they are stored in one .accdb file.
Class activity

“Find the field type”: cards name pieces of data (date of birth, surname, payment amount, “yes/no”, a photo); students point out the matching field type.

Practice
1
Which Number size is enough for a score from 0 to 100, and why?
2
Which field type increases by itself with each new record?
3
How many characters can a Short Text field hold?
4
Why is Currency chosen for a payment amount rather than Number?