Building Simple DatabasesIntroduction
To learn the basics of &kexi;, you could build a simple database
utilizing most elementary &kexi;'s features. To make things simpler,
advanced database design topics will not be covered here.
Start by creating a new empty Phone Book.
Having a new empty database project, perform the following steps:Design database tables. Read .Enter data into tables. Read .Design database queries. Read .Design forms. Read .Use forms to enter data. Read .Designing Database Tables
First, there will be two tables added to your database:
persons and phone_numbers.
These are exactly the same tables as described in chapter Database and spreadsheet.
A layout for Persons can be found in section
Data integrity and validity
in that chapter.
Select InsertTable from the Menubar. You can also use the button Create
object: table on the Project
Navigator's toolbar.
The Table Designer's window will appear. Looking at the top of designer's window
you will notice that &kexi; proposed you a generic name like
template for the new table. The table design is not saved
yet so you will be able to assign more proper name later. Moreover, because of
the same reason, the table name is not yet visible in the
Project Navigator.
The Table Designer windowTable Designer window consists of following columns:PK - Primary Key.
Field Caption - caption of the field
which will be displayed during data entering.
Data Type - a combo box containing a list of data types,
allowing to set a main rule for entered data for a given field. For example,
when an integer number data type is set for a field, a database user will not
able to enter letter characters into this field.
Comments - you can enter here any information useful for
understanding what the given field is provided for. This additional text will
be saved within the table design and only visible in design mode.
In the Table designer window, every row corresponds to
a single table field. You can recognize you are in design
mode because the
Switch to Design View mode button is toggled on within
the main &kexi; toolbar.
Designing the Persons table
In the first row click on the cell in the Field Caption
column and enter Name as field caption.
Notes about field names and captions
Every table field must have a name and a caption, these cannot be empty.
Field name is a word used by the database, usually not visible for users of the database application. The name may not contain special (national) characters (like ±, ¶, Ü)
or space characters. The name must only contain roman letters,
numbers and underscore sign "_". Use the latter instead of
spaces or dashes.
Field names must be started with a letter or underscore sign
"_", never with a number.
It does not matter whether you are using small or capital letters.
For &kexi; the database name "Persons" is the same as
"persons".
Field caption, on the other hand, allows you to enter any letters and special characters. It will be displayed for users of the database application.
In a similar way, enter the following fields into the table design:surnamestreethouse_numbercity
All the above fields, except house_number, are of type
text.
Change house_number field's type to integer
number. To do this, click on a cell in the Data
Type column, house_number row and then
click on drop down list's button
(you can also press F4 or
&Alt;Down. The list
of data types will appear. Select the Integer number type.
From now on, the house_number field only accepts numbers.
Persons table design is ready. Click
Switch to Data View button on the toolbar to finish
designing and switch to Data View for the table. This allows you entering
data into the table.
As the design is not yet saved in the database, the Save Object As
dialog window appears. You need to specify the name for the new table.
&kexi; offers a generic name like Table1.
To change the name, enter Persons into the
Caption field and press the Enter key or click the OK
button. The Caption field will be used to display the
table to database end-users, ⪚ as a form. Unlike the name, the caption can
contain any characters including spaces and special characters.
Note that filling the Caption field automatically fills
the Name field. For your convenience the rule for using
only letters, numbers and the "_" character is kept. You
can alter the contents of the Name field if you want to.
You are asked about an agreement for automatic adding of primary key to the table.
Click Add primary key
button to continue.
The Persons table has been created and opened in Data View.
Its name appears in the Project Navigator pane.
Create the phone_numbers table, in a similar
way as persons table.
Create a person field of type Integer
number and phone of type Text.
Do not use a number type here because phone numbers can have many different
forms and prefixes.
Click Switch to
Data View button on the toolbar and enter Phones
caption for the table. As for your previous table, allow &kexi; to automatically
create a primary key.
&enteringdataintotables;
&querydesigning;
&designingforms;
&enteringdatausingforms;