ShareWare OnLine 2/ShareWare OnLine Volume 2 (CMS Software)(1993).iso/prog/dtbl11.zip/DEMO4.FRM

Visual Basic Form | 1993-05-11 | 13KB | 238 lines

Form1
!DataTable Example Program - DEMO4
Form1
Customer
    DATATABLE
C:\CUSTOMER
Label1
Name:
CustomerName
Label2
Address:
Address
Label3
City:
Label4
State:
State
Label5
Label6
Phone:
Phone
    TopButton
NextButton
InsertButton
Insert
DeleteButton
Delete
QuitButton
BottomButton
Bottom
PreviousButton
Previous
UpdateButton
Update
ClearButton
Clear
QuitButton_Click
Form_Click
    Form_Load>
Customer
    OpenTableg
Action
CloseTable%
FillForm
    GetRecord
    FieldName
GetField
CustomerName:
Text$
FieldValue
Address
StateW
Phone}
    InsertRecW
PutField
InsertRecord
InsertButton_Click
ClearButton_Click
TopButton_Click
FirstRecord
BottomButton_Click
LastRecord
NextButton_ClickA
NextRecord
PreviousButton_ClickJ
PreviousRecord
DeleteButton_Click
DeleteRecord4
    UpdateRec
UpdateRecord
UpdateButton_Click
Reaction
DisplayError
TheError
CustomerName_Change
CustomerName_LostFocus
SearchMode
SEARCHFIRST
SearchField
TheNameTyped'
database
tableN
    DataTable
    KeySearch
    SearchKey
FillCustomerCombo
EmptyCustomerCombo
    ListCount
Form_Load
Open up the database table
Fill the combo box with customer names
Now fill the form with data
in the first record.
QuitButton_Click
Close the database table
And quit the program
FillForm
We need to get the current record in the database:
Ok, now lets get the values in the database fields for the
record we just read in::
We need to make a one-to-one relationship between the fields in the database table
and the fields on our Visual Basic Form. We will read in the field values from the
database record and place those values into the .TEXT property of our TEXT controlss
on our Visual Basic form. For each field of interest this is a three-step process:
1. Specify the name of the database field of interest ---> DataTable.FieldName = "
2. Get the field value ---> DataTable.Action = GetFieldd
3. Place the field value in the TEXT control ---> Text1.TEXT = DataTable.FieldValuee
Thats all there is to it!!
You should make a FillForm like subroutine position independent. Notice that the first line of
code in this subroutine reads in the current record. Use other routines to move around
in the table (like the TOP,BOTTOM, NEXT and PREVIOUS buttons in this demo). Making the
routine position independent means that it can be used and re-used at any time to fill inn
your form with information from any record in your database.
We will fill in the form now:o
Address"
State"
Phone"
InsertRec
Here we transfer the information from the Visual Basic Form and insert itt
into the database table.
To do this requires a three-step process for each field in the database table:
1. Specify the name of the field of interest ---> DataTable.FieldNamee
2. Specify the field value ---> DataTable.FieldValue = A String valuee
3. Put the field into the DataTable record ---> DataTable.Action = PutFieldd
We do this for each field in the database table.
When we are finished we INSERT the record into the
database table ---> DataTable.Action = InsertRecordd
Address"
State"
Phone"
InsertButton_Click
ClearButton_Click
This code simply clears the text in all of the Visual Basic form's Text controls..
TopButton_Click
The following code moves to the first record in the data basen
and fills in our form with the information found in that first
record
Moveto the first record in the database
Fill in the form with data
BottomButton_Click
The following code moves to the last record in the data base
and fills in our form with the information found in that last
record
Move to the last recordd
Fill the form
NextButton_Click
The following code moves to the next record in the database table. If an
error is encountered during the move to the next record an error message is displayed.
The DisplayError subroutine is an example of the structure of a generalized
DataTable error handling routine.
Once the repositioning to the next record is successfull, we fill in our form
with information from that record.
Moving to the next record in the databaseu
If an errort
Display the DataTable errore
If no error
Fill in our form with the information in the record.
PreviousButton_Click
The following code moves to the previous record in the database table. If an
error is encountered during the move to the record an error message is displayed.a
The DisplayError subroutine is an example of the structure of a generalizedl
DataTable error handling routine.
Once the repositioning to the previous record is successfull, we fill in our forma
with information from that record.
Moving to previous records
If an errors
Display the DataTable Errorr
If no error
Fill in our form with info from the record
DeleteButton_Click
This code deletes the current record from the database
The current record after the delete is performed, is the record immediatelyr
following the deleted record. We then fill in our form with info from that
record.n
We will delete the current record.
Now fill in form with the current record.
UpdateRec
Here we transfer the information from the Visual Basic Form and update the current record
in the database table.
To do this requires a three-step process for each field in the database table:
1. Specify the name of the field of interest ---> DataTable.FieldNames
2. Specify the field value ---> DataTable.FieldValue = A String values
3. Put the field into the DataTable record ---> DataTable.Action = PutFieldl
We do this for each field in the database table.
When we are finished we UPDATE the record in the
database table ---> DataTable.Action = UpdateRecordd
Address"
State"
Phone"
UpdateButton_Click
DisplayError
Here we show how to build a general purpose error routine for the DataTablee
it is not complete but gives you the basic idea of how to build such a routine..
For a listting of all DataTable error codes see the Working Model documentation.
Drive not ready!
Directory not found!
File is busy!"
File is Locked!"
File not Found!"
 Record not Found!
End of Table!"
Start of Table!"
Unknown Error!
CustomerName_LostFocus
This code demonstrates how to search a database on a specific key.
When you leave this field, this lost focus subroutine is executed.
The value in the CustomerName.Text is then searched for in the database table.
The database field searched is "Name" (The only key field in this example).l
If the search is successfull the record is displayed on the form. If the search
fails an error message is displayed, the form is cleared (with the typed in value)
replaced in the CustomerName.Text expecting to get a new customer's information.
Temporary variable to hold Customer's name.c
The first and only field in PRIMARY index
The first and only field of the keye
The value to search forf
Submit the search criteria
Perform the search
If an errorh
Display the errort
Assume new customer, temp store for new customer name'
Clear the form
Place the new customer name back in the form
Now let the user type in the new infoa
Search was successfull
Fill in the form with customer infoa
FillCustomerCombo
Move to first record in the CUSTOMER database
We want to put customer names in the combo box
Loop to fill combo box with customer names
Get the record
Get the customer named
Add name to the list
Move to next recorde
Reposition to the first record
EmptyCustomerCombo
Here we empty the combo box to eliminate duplicate names
Loop to remove names from list