Topic: Data Modelling (I)
Subtopic: Creating Blank Database
Instructional Objectives: by the end of the lesson, the learners should be able to create a new database.
Instructional Materials: Computer System, Ms Access software, practical video.
Note: Scroll down to the end of this note for video.
The term Database can be defined as the collection of information that is organised in a predictable structured way. It is usually set up in order to meet the information requirements of the major part of an organisation.
Database packages are used to design a database in a computer. Example of a common database package is Microsoft Access. MS Access is a Relational Database Management System used to create and modify databases.
Generally, creating database using any DBMS entails the following basic steps:
Define the Database Structure
The database structure specifies the type of database organization that should be used. If the relational form is selected, the database structure will include RDBMS, structure of table, number of rows, number of columns, the key, and relationship of the database etc.
SPECIFYING FIELD TYPE
When a database is being created, all fields are set to accept a particular type of input by specifying a field type. A field type is also known as a Data type. The essence of a data type is to prevent a wrong input from being stored in a database (i.e. database integrity). Usually the name of a data type varies with DBMS but portrays a general meaning. These include;
Alpha numeric/ text field: Fields that accepts both numbers and text e.g. ASP2548.
Numeric Fields: Fields that accepts numbers in two forms: Real number i.e. decimal numbers e.g. 8.15, 9.1 and integers’ i.e. whole numbers e.g. 125, 80 etc.
Date Fields: They store data in date format e.g. 11-04-2009
Boolean fields: The data accepted by these fields are either Yes/No or True/False.
Memo: Long text. Use for long pieces of text. Such as notes and long description. Can store up to 64,000 characters.
Currency: Use for currency.
AutoNumber: Unique sequential numbers or random number automatically inserted when you create a record. Use to create primary key.
Hyperlink: Use to store hyperlink
Attachment: use to store attachments e.g files, images etc.
OLE Object: OLE stands for object linking and embedding. Use to attach an OLE object such as word document, Spreadsheet, or Powerpoint Presentation, sound, picture, etc.
After the field names and their data types have been specified, then records are stored in the database by specifying the appropriate input.
To keep database updated, data inputted into the database must be saved regularly. Keyboard command CTRL + S is used. Alternatively, you click on the Office button and save.
Starting Microsoft Access And A New Database
To create a database on the computer with MS Access
Load MS Access: do the following;
- Click on the Start Menu or button
- Move the mouse to All program menu
- locate Microsoft Access in the list of programs and click on it.
Depending on the version of window, a window with three main option will display and you are expected to choose one.
- Blank database or new database: when this option is selected, it will enable you design and create the Data Base from scratch.
- Project (New Data) or database wizard: this option will display a list of common databases and automatically creates the one you select.
- Project (existing data) or open existing database: this option will allow you to open an existing or previously created and saved database.
for the sake of this lesson which is creating new database, we will move to step 4 below.
4. Select the blank database option and click on it.
5. select the drive in which you want to store the new database.
6. Type in the file name of your choice, then click the create button.
Note: there are certain basic rules which must be observed or followed when specifying field names, table names, form names etc. These rules are:
- The name must not exceed 64 characters.
- Any combination of characters including space, underscore, (_), special characters may be used.
- Periods (.), Is not permissible.
7. The computer then create the new database file name used. After that the database window will be opened. Watch the video below for guide.
Done Studying? See previous Lesson in Data Processing
- What is database?
- What are data types you can specify in Ms-Acess?
- List the steps involve in loading Ms Access or blank database.