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Before going to do any Database Program ,Click here to understand Database Concepts thoroughly.
That is , Creating Database within VB Platform
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(A) Creating a database :
(Refer Linking to Database)
Creating a database using Access(97) and creating a table.
- Open Access, select Blank Database, then OK
- Give a name (say db1) , then click Create
- Select create table in Design View from the dialog window, and OK
- Now we will get a window showing three fields a s Field Name,Data Type and Description
- In that window, fill the information as FieldData bTypeidTextNameText
DOBDate/TimeAddressTextPinNumber
- Right Click on id , then select Primary Kay from the drop down list ..to make the id field a primary key(Because id has to unique and non null value)
- Click on Close button
- Then a dialog box will appear telling you to give a table name for the created table(Give a name for the table,say, Student Master)
So.now what you get is a database named db1.mdb , with a table named Student Master with no records in it.
Now fill in the recorde in the table and close the window.
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(B) Providing a front end through VB to link with the DataBase :
Now fill in the recorde in the table and close the window.
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(B) Providing a front end through VB to link with the DataBase :
Open VB three times.(Activate three instances in VB)
- Standard EXE (As we normally doing)
- ActiveX DLL
- ActiveX EXE
Note :
- When the Save button in the form of Standard EXE is pressed, all the details entered should be verified and then passed on to the ActiveX DLL program.ActiveX DLL program is one ,which will implement all the business rules in the project.
- ActiveX DLL program is going to check all the business rules and then pass the data to ActiveX EXE program
- ActiveX EXE program is one,which is going to access the database and write the data provided by the ActiveX DLL in the database.This process will be loaded on the server.
1 ) Standard EXE
Create a Standard EXE program,containing a form to accept the student details from the user.
Draw the form as
Insert 5 Labels, 5 TextBoxes, and one Command Button.
Change the captions of the components a s follows : Label1 to Student ID,
, Label2 to Name, Label3 to DOB , Label4 to Address, Label5 to Pin . And delete the captions of all the TextBoxes, and change the caption of Command Button to Save as shown above:
Name the project as ClientEnd and form as StudentEntryForm . This project will be loaded in the client machine.
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2 ) ActiveX DLL
Now,again invoke the second instances of VB and choose ActiveX DLL as the project type.
We can see that there is a class module present by default.Click on the name property of the class module and type studentclass in the place of class1. In the same way,again click on the project window and rename the project to Businessrules.
Tools--> Add Procedure :
- Now include some properties into the class studentclass , by clicking the Tools--> add procedure option.
- Select type as property , and scope as public.
- In the place of name, type studid , then press OK.
Now , we will get a code window as :
Public Property Get Studid() As Variant End Property Public Property Let Studid(ByVal vNewValue As Variant) End Property |
And, you will get the following code in the code window.
Code NO : 1
Public Property Get Studid() As Variant End Property Public Property Let Studid(ByVal vNewValue As Variant) End Property |
Public Property Get studname() As Variant End Property Public Property Let studname (ByVal vNewValue As Variant) End Property |
Public Property Get studdob() As Variant End Property Public Property Let studdob (ByVal vNewValue As Variant) End Property |
Public Property Get studadd() As Variant End Property Public Property Let studadd (ByVal vNewValue As Variant) End Property |
Public Property Get studpin() As Variant End Property Public Property Let studpin (ByVal vNewValue As Variant) End Property |
Now create five private data members(variables) for the class as shown below :
Code NO : 2
Private sid As String Private sname As String Private sdob As Date Private sadd As String Private spin As Integer |
Code NO : 3
Public Property Get studid() As String studid = sid End Property Public Property Let studid(ByVal vNewValue As String) sid = vNewValue End Property |
Public Property Get studname() As String studname = sname End Property Public Property Let studname(ByVal vNewValue As String) sname = vNewValue End Property |
Public Property Get studadd() As String studadd = sadd End Property Public Property Let studadd(ByVal vNewValue As String) sadd = vNewValue End Property |
Public Property Get studpin() As String studpin = spin End Property Public Property Let studpin(ByVal vNewValue As String) spin = vNewValue End Property |
Public Property Get studdob() As String studdob = sdob End Property Public Property Let studdob(ByVal vNewValue As String) sdob = vNewValue End Property |
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3 ) ActiveX EXX
Now,again invoke third instance of VB and choose ActiveX EXE as the project type.You can see that , again there is a default class module with class1 as default class in it. Change the name of the project to backend and class to backendclass .
Create private data members(variables) for backend class by writing the following code in the code window of the class backendclass.
Code NO : 1
Private bsid As String Private bsname As String Private bsdob As Date Private bsadd As String Private bspin As Integer |
Enter the following code to add the procedures in the class backendclass.
Code NO : 2
Private Sub class_initialize() set db=open database("Give path of db1.mdb") End Sub |
Public Property Get stid() As String stid = bsid End Property Public Property Let stid(ByVal vNewValue As String) bsid = vNewValue End Property |
Public Property Get stname() As String stname = bsname End Property Public Property Let stname(ByVal vNewValue As String) bsname = vNewValue End Property |
Public Property Get stadd() As String stadd = bsadd End Property Public Property Let stadd(ByVal vNewValue As String) bsadd = vNewValue End Property |
Public Property Get stpin() As Integer stpin = bspin End Property Public Property Let stpin(ByVal vNewValue As String) bspin = vNewValue End Property |
Public Property Get studdob() As Date stdob = bsdob End Property Public Property Let stdob(ByVal vNewValue As Date) bsdob = vNewValue End Property |
Enter the following commands in the class declaration to establish a connection with the database.
Code NO : 3
Dim db as Database Dim rs as Recordset |
Private Sub class_initialize() set db=open database("Give path of db1.mdb") End Sub |
(Not complete......)
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