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Manage() provides data management functionality for your application and/or process.
Below is the code for Manage():
'
' Manage()
'
' This function performs simple record functions of add, delete and gets
'
Sub Manage()
Console.WriteLine("MANAGE")
' populate the tables with data
Add_CustomerMaster_Records()
Add_ItemMaster_Records()
Add_Transactions()
' display the orders and their items
Display_CustomerOrders()
Display_OrderItems()
End Sub
'
' Add_CustomerMaster_Records()
'
' This function adds records to table CustomerMaster from an
' array of strings
'
Public Structure CUSTOMER_DATA
' struct members
Public number, zipcode, state, rating, name, address, city As String
' struct constructor
Public Sub New(ByVal number As String, ByVal zipcode As String, ByVal state As String, ByVal rating As String, ByVal name As String, ByVal address As String, ByVal city As String)
Me.number = number
Me.zipcode = zipcode
Me.state = state
Me.rating = rating
Me.name = name
Me.address = address
Me.city = city
End Sub
End Structure
Sub Add_CustomerMaster_Records()
Dim data(3) As CUSTOMER_DATA
data(0) = New CUSTOMER_DATA("1000", "92867", "CA", "1", "Bryan Williams", "2999 Regency", "Orange")
data(1) = New CUSTOMER_DATA("1001", "61434", "CT", "1", "Michael Jordan", "13 Main", "Harford")
data(2) = New CUSTOMER_DATA("1002", "73677", "GA", "1", "Joshua Brown", "4356 Cambridge", "Atlanta")
data(3) = New CUSTOMER_DATA("1003", "10034", "MO", "1", "Keyon Dooling", "19771 Park Avenue", "Columbia")
Dim nRecords As Integer = data.Length
Delete_Records(recordCustMast)
Console.WriteLine(ControlChars.Tab + "Add records in table CustomerMaster...")
Try
' start a transaction
recordCustMast.Begin()
Dim i As Integer
For i = 0 To nRecords - 1
recordCustMast.Clear()
' populate record buffer with data
recordCustMast.SetFieldAsString(0, data(i).number)
recordCustMast.SetFieldAsString(1, data(i).zipcode)
recordCustMast.SetFieldAsString(2, data(i).state)
recordCustMast.SetFieldAsString(3, data(i).rating)
recordCustMast.SetFieldAsString(4, data(i).name)
recordCustMast.SetFieldAsString(5, data(i).address)
recordCustMast.SetFieldAsString(6, data(i).city)
' add record
recordCustMast.Write()
Next
' commit transaction
recordCustMast.Commit()
Catch E As CTException
Handle_Exception(E)
End Try
End Sub
'
' Add_ItemMaster_Records()
'
' This function adds records to table ItemMaster from an
' array of strings
'
Public Structure ITEM_DATA
' struct members
Public weight As Integer
Public price As CTMoney
Public itemnum, description As String
' struct constructor
Public Sub New(ByVal weight As Integer, ByVal price As CTMoney, ByVal itemnum As String, ByVal description As String)
Me.weight = weight
Me.price = price
Me.itemnum = itemnum
Me.description = description
End Sub
End Structure
Sub Add_ItemMaster_Records()
Dim data(3) As ITEM_DATA
Data(0) = New ITEM_DATA(10, 1995, "1", "Hammer")
Data(1) = New ITEM_DATA(3, 999, "2", "Wrench")
Data(2) = New ITEM_DATA(4, 1659, "3", "Saw")
Data(3) = New ITEM_DATA(1, 398, "4", "Pliers")
Dim nRecords As Integer = Data.Length
Delete_Records(recordItemMast)
Console.WriteLine(ControlChars.Tab + "Add records in table ItemMaster...")
Try
' start a transaction
recordItemMast.Begin()
Dim i As Integer
For i = 0 To nRecords - 1
recordItemMast.Clear()
' populate record buffer with data
recordItemMast.SetFieldAsSigned(0, Data(i).weight)
recordItemMast.SetFieldAsMoney(1, Data(i).price)
recordItemMast.SetFieldAsString(2, Data(i).itemnum)
recordItemMast.SetFieldAsString(3, Data(i).description)
' add record
recordItemMast.Write()
Next
' commit transaction
recordItemMast.Commit()
Catch E As CTException
Handle_Exception(E)
End Try
End Sub
'
' Delete_Records()
'
' This function deletes all the records in the table
'
Sub Delete_Records(ByVal record As CTRecord)
Dim found As Boolean
Console.WriteLine(ControlChars.Tab + "Delete records...")
Try
' write lock required for transaction updates
record.Lock(LOCK_MODE.WRITE_LOCK)
' start a transaction
record.Begin()
' read first record
found = record.First()
While (found) ' while records are found
' delete record
record.Delete()
' read next record
found = record.Next()
End While
' commit transaction
record.Commit()
' free locks
record.Unlock()
Catch E As CTException
record.Abort()
Handle_Exception(E)
End Try
End Sub
'
' Add_Transactions()
'
' Add an Order and associated Items "as a transaction" to their
' respective tables. A transaction is committed or aborted if the
' customer number on the order is confirmed valid. Likewise each
' item in the order is verified to be a valid item. SavePoints are
' established as an order is processed, allowing a transaction to
' rollback to the previously verified item
'
Public Structure ORDER_DATA
' struct members
Public orderdate, promdate, ordernum, custnum As String
' struct constructor
Public Sub New(ByVal orderdate As String, ByVal promdate As String, ByVal ordernum As String, ByVal custnum As String)
Me.orderdate = orderdate
Me.promdate = promdate
Me.ordernum = ordernum
Me.custnum = custnum
End Sub
End Structure
Public Structure ORDERITEM_DATA
' struct members
Public ordernum As String
Public seqnumber, quantity As Integer
Public itemnum As String
' struct constructor
Public Sub New(ByVal ordernum As String, ByVal seqnumber As Integer, ByVal quantity As Integer, ByVal itemnum As String)
Me.ordernum = ordernum
Me.seqnumber = seqnumber
Me.quantity = quantity
Me.itemnum = itemnum
End Sub
End Structure
Sub Add_Transactions()
Dim orders(2) As ORDER_DATA
orders(0) = New ORDER_DATA("09/01/2002", "09/05/2002", "1", "1001")
orders(1) = New ORDER_DATA("09/02/2002", "09/06/2002", "2", "9999") ' bad customer number
orders(2) = New ORDER_DATA("09/22/2002", "09/26/2002", "3", "1003")
Dim nOrders As Integer = orders.Length
Dim items(5) As ORDERITEM_DATA
items(0) = New ORDERITEM_DATA("1", 1, 2, "1")
items(1) = New ORDERITEM_DATA("1", 2, 1, "2")
items(2) = New ORDERITEM_DATA("2", 1, 1, "3")
items(3) = New ORDERITEM_DATA("2", 2, 3, "4")
items(4) = New ORDERITEM_DATA("3", 1, 2, "3")
items(5) = New ORDERITEM_DATA("3", 2, 2, "99") ' bad item number
Dim nItems As Integer = items.Length
Dim orderdate As CTDate = New CTDate()
Dim promdate As CTDate = New CTDate()
Dim savepoint As Integer
Dim j As Integer = 0
Delete_Records(recordCustOrdr)
Delete_Records(recordOrdrItem)
Console.WriteLine(ControlChars.Tab + "Add Transaction Records...")
' process orders
Dim i As Integer
For i = 0 To nOrders - 1
' start a transaction
MySession.Begin()
Try
recordCustOrdr.Clear()
' populate record buffer with order data
orderdate.StringToDate(orders(i).orderdate, DATE_TYPE.MDCY_DATE)
promdate.StringToDate(orders(i).promdate, DATE_TYPE.MDCY_DATE)
recordCustOrdr.SetFieldAsDate(0, orderdate)
recordCustOrdr.SetFieldAsDate(1, promdate)
recordCustOrdr.SetFieldAsString(2, orders(i).ordernum)
recordCustOrdr.SetFieldAsString(3, orders(i).custnum)
' add order record
recordCustOrdr.Write()
Catch E As CTException
Handle_Exception(E)
End Try
' set transaction savepoint
savepoint = recordCustOrdr.SetSavePoint()
' process order items
While (items(j).ordernum = orders(i).ordernum)
Try
recordOrdrItem.Clear()
' populate record buffer with order item data
recordOrdrItem.SetFieldAsSigned(0, items(j).seqnumber)
recordOrdrItem.SetFieldAsSigned(1, items(j).quantity)
recordOrdrItem.SetFieldAsString(2, items(j).ordernum)
recordOrdrItem.SetFieldAsString(3, items(j).itemnum)
' add order item record
recordOrdrItem.Write()
' check that item exists in ItemMaster table
recordItemMast.Clear()
recordItemMast.SetFieldAsString(2, items(j).itemnum)
If (recordItemMast.Find(FIND_MODE.EQ) <> True) Then
' if not found, restore back to previous savepoint
recordItemMast.RestoreSavePoint(savepoint)
Else
' set transaction savepoint
savepoint = recordItemMast.SetSavePoint()
End If
Catch E As CTException
Handle_Exception(E)
End Try
' bump to next item
j += 1
' exit the while loop on last item
If (j >= nItems) Then
Exit While
End If
End While
' check that customer exists in CustomerMaster table
recordCustMast.Clear()
recordCustMast.SetFieldAsString(0, orders(i).custnum)
' commit or abort the transaction
If (recordCustMast.Find(FIND_MODE.EQ) <> True) Then
MySession.Abort()
Else
MySession.Commit()
End If
Next
End Sub
'
' Display_CustomerOrders()
'
' This function displays the contents of a table. ctdbFirstRecord() and
' ctdbNextRecord() fetch the record. Then each field is parsed and displayed
'
Sub Display_CustomerOrders()
Dim custnumb As String
Dim ordrnumb As String
Console.WriteLine(ControlChars.Tab + "CustomerOrder table...")
Try
' read first record
If (recordCustOrdr.First()) Then
Do
ordrnumb = recordCustOrdr.GetFieldAsString(2)
custnumb = recordCustOrdr.GetFieldAsString(3)
' display data
Console.WriteLine(ControlChars.Tab + " {0} {1}", ordrnumb, custnumb)
Loop While (recordCustOrdr.Next()) ' read next record until end of file
End If
Catch E As CTException
Handle_Exception(E)
End Try
End Sub
'
' Display_OrderItems()
'
' This function displays the contents of a table. ctdbFirstRecord() and
' ctdbNextRecord() fetch the record. Then each field is parsed and displayed
'
Sub Display_OrderItems()
Dim itemnumb As String
Dim ordrnumb As String
Console.WriteLine(ControlChars.NewLine + ControlChars.Tab + "OrderItems Table...")
Try
' read first record
If (recordOrdrItem.First()) Then
Do
' get field data from record buffer
ordrnumb = recordOrdrItem.GetFieldAsString(2)
itemnumb = recordOrdrItem.GetFieldAsString(3)
' display data
Console.WriteLine(ControlChars.Tab + " {0} {1}", ordrnumb, itemnumb)
Loop While (recordOrdrItem.Next()) ' read next record until end of file
End If
Catch E As CTException
Handle_Exception(E)
End Try
End Sub
