Installment system with invoice dividing in VB.NET - vb.net

Question

I'm fighting with something for a couple of days and I really need help from You because it's too difficult for me.
There are many debtor customers of the company I work in. Sometimes they cannot pay off all debt so they would like to pay off their arrears in installment/loan system. I'm working on it using VB.NET. I have to prepare the shedule which will divide every installment for individual invoices. I could easily split invoices to installments with payment deadlines for each one, but after that, in the second step, I have to divide each installment on invoices. There is an example of this accounting made manually in Excel for 2 exemplary invoices below. I know that loops used in the code should have 2 "if" conditions: Condition1: Installment amonunt < Invoice amount and Condition2: Installment amonunt >= Invoice amount, but app user (employee of the debt collection department) can generate mixed shedule (various amounts of each installment) where both of condition can be met.
Additionally the simplification is that the program will not charge interest at all (higher level[! decision).
I'll be very thankful for any help or any clue to solve this problem.
Maybe some of You have had such a problem before 🙂
Thanks in advance!

Answer 1

For accounting application, we have a matching table to bridge between the invoice and receipt(Instalment). When an instalment is scheduled, you match to the invoice accordingly base on FIFO. So you need to update the data to the matching table and at the same time you need to have a Amount Match and Amountunmatched field on you invoice to keep track of the partial payment.
so when the first schedule is done
Instalment : Inst 1
Invoice : Inv A
Amtmatched : 50
MatchDate : 2021-05-15
Debtor : ABC
At the same time you need update the Invoice A amountmatched to 50 and amountunmatched to 106.53 (outstanding)
2nd Instalement
Instalment : Inst 2
Invoice : Inv A
Amtmatched : 50
MatchDate : 2021-06-15
Debtor : ABC
3rd Instalement
Instalment : Inst 3
Invoice : Inv A
Amtmatched : 50
MatchDate : 2021-07-15
Debtor : ABC
4th Instalement, you need to update 2 records
Instalment : Inst 4
Invoice : Inv A
Amtmatched : 6.53
MatchDate : 2021-08-15
Debtor : ABC
Instalment : Inst 4
Invoice : Inv B
Amtmatched : 43.47
MatchDate : 2021-08-15
Debtor : ABC
You can see this patter is very similar to your table.
On the programming part, you need a date input of startdate, and number of instalment to work the amount for each instalment and the last instalment. You can use the oustanding divide by the outstanding and round it off and get the round off figure allocate to the last month.
Save the instalment schedule to a table first. After that loop the instalment schedule and generate the matching table and update the invoice outstanding for each loop. If you think this method can do the trick and you need further help. You just buzz me.

Answer 2

This is the database diagram and some data sample
This is the program UI
I will put in the number of instalment I want to schedule and Instalment prefix to generate the transaction no for the instalment.
Here goes the code
Imports System.Data.SqlClient
Public Class frmInstalment
Private Sub btnGenerateInstalment_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGenerateInstalment.Click
Dim TotalOustanding = Modws.GetDecimalFromQuery("Select Sum(amtunmatched) from Invoice")
Dim InstNo As Integer = Val(txtInstalmentNo.Text)
Dim Balance = TotalOustanding
Dim i As Integer = 1
Do Until i = InstNo + 1
Dim InstalAmount = Math.Ceiling(TotalOustanding / InstNo)
Balance = Balance - InstalAmount
Dim Amount As Decimal
If Balance > 0 Then
Amount = InstalAmount
Else
Amount = InstalAmount + Balance
End If
Dim InstalNo As String = txtInsalPre.Text & i.ToString("00")
Modws.UpdateItem("Insert into Instalment(TransNo,Instalment,Amount) Values('" & InstalNo & "'," & i & ", " & Amount & ")")
i = i + 1
Loop
Modws.DisplayDataGrid(dgvInstalment, "Select TransNo,Instalment,Amount from Instalment Order by TransNo")
For x = 0 To dgvInstalment.Rows.Count - 1
AddMatching(dgvInstalment("TransNo", x).Value, Val(dgvInstalment("Amount", x).Value))
Next
Modws.DisplayDataGrid(dgvResult, "Select * from Matching Order by Instalment")
End Sub
Private Sub AddMatching(InstalmentNo As String, InstAmt As Decimal)
Dim StrConn As String = My.Settings.ImportLinkCS
Dim CN = New SqlConnection(StrConn)
CN.Open()
Dim StrSql As String = "Select * from Invoice Where AMTUNMATCHED <> 0 order by transdate, TransNo"
Dim cmdReader As SqlCommand = New SqlCommand(StrSql, CN)
cmdReader.CommandType = CommandType.Text
Dim SdrReader As SqlDataReader = cmdReader.ExecuteReader(CommandBehavior.CloseConnection)
'SdrReader = cmdReader.ExecuteReader
Try
With SdrReader
If .HasRows Then
While .Read
If .Item("Amtunmatched") > InstAmt Then
Modws.UpdateItem("Update Invoice set amtmatched = amtmatched + " & InstAmt & ",amtunmatched = amtunmatched - " & InstAmt & " Where TransNo = '" & .Item("TransNo") & "'")
Modws.UpdateItem("Insert into Matching(Invoice,Instalment,Amtmached,InvOutstanding) " + _
"Values('" & .Item("TransNo") & "','" & InstalmentNo & "', " & InstAmt & "," & (.Item("Amtunmatched") - InstAmt) & " )")
Exit Sub
Else
Modws.UpdateItem("Update Invoice set amtmatched = Total,amtunmatched = 0 Where TransNo = '" & .Item("TransNo") & "'")
Modws.UpdateItem("Insert into Matching(Invoice,Instalment,Amtmached,InvOutstanding) " + _
"Values('" & .Item("TransNo") & "','" & InstalmentNo & "'," & .Item("AMTUNMATCHED") & ",0 )")
InstAmt = InstAmt - .Item("Amtunmatched")
End If
End While
End If
End With
Catch ex As System.Exception
MsgBox(ex.Message, MsgBoxStyle.Critical, "Error")
End Try
End Sub
Private Sub btnReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnReset.Click
Modws.DeleteItem("Delete from Instalment")
Modws.DeleteItem("Delete from Matching")
Modws.UpdateItem("Update Invoice set amtmatched = 0, amtunmatched = Total")
End Sub
End Class
You also need to add a module class in your program
Imports System.Data
Imports System.Data.SqlClient
Imports ImportLink.GridPrintPreviewLib
Module Modws
Public Function GetDecimalFromQuery(ByVal SQLQuery As String) As Decimal
Dim StrConn As String = My.Settings.ImportLinkCS
Dim CN = New SqlConnection(StrConn)
GetDecimalFromQuery = 0
CN.Open()
Dim StrSql As String = SQLQuery
Dim cmdReader As SqlCommand = New SqlCommand(StrSql, CN)
cmdReader.CommandType = CommandType.Text
Dim SdrReader As SqlDataReader = cmdReader.ExecuteReader(CommandBehavior.CloseConnection)
'SdrReader = cmdReader.ExecuteReader
'GetDoubleFromQuery = 0
Try
With SdrReader
If .HasRows Then
While .Read
If .GetValue(0) Is DBNull.Value Then
'GetDoubleFromQuery = 20
'MsgBox("Null Value")
Else
If IsDBNull(.GetValue(0).ToString) Then
'GetDoubleFromQuery = 50
'MsgBox("Null Value")
Else
GetDecimalFromQuery = .GetValue(0).ToString
End If
End If
End While
Else
'MsgBox("No Row")
End If
End With
CN.Close()
Catch ex As Exception
MsgBox(ex.Message, MsgBoxStyle.Exclamation, "Error")
End Try
End Function
Public Sub UpdateItem(ByVal SqlQuery As String)
Dim StrConn As String = My.Settings.ImportLinkCS
Dim CN = New SqlConnection(StrConn)
Try
CN.Open()
Dim StrSql As String = SqlQuery
Dim cmdupdate As New SqlCommand(StrSql, CN)
cmdupdate.CommandText = StrSql
cmdupdate.ExecuteNonQuery()
Catch ex As Exception
MsgBox(ex.Message & SqlQuery, MsgBoxStyle.Exclamation, "Error-UpdateItem")
End Try
CN.Close()
CN = Nothing
End Sub
Public Sub DisplayDataGrid(ByVal dgv As DataGridView, ByVal SQLSTR As String)
dgv.DataSource = Nothing
Try
Dim dbBindSource As New BindingSource
Dim strCon As String = My.Settings.ImportLinkCS
Dim strSQL As String = SQLSTR
Dim dataAdapter As SqlDataAdapter = New SqlDataAdapter(strSQL, strCon)
Dim commandBuilder As SqlCommandBuilder = New SqlCommandBuilder(dataAdapter)
'Populate a new data table and bind it to the BindingSource.
Dim table As DataTable = New DataTable()
table.Locale = System.Globalization.CultureInfo.InvariantCulture
dataAdapter.Fill(table)
dbBindSource.DataSource = table
'Resize the DataGridView columns to fit the newly loaded content.
dgv.AutoResizeColumns(DataGridViewAutoSizeColumnsMode.AllCellsExceptHeader)
dgv.DataSource = dbBindSource
dgv.Columns(2).Width = 200
Catch ex As Exception
MsgBox(ex.Message, MsgBoxStyle.Critical, "error")
End Try
End Sub
End Module
And This is the result I'm getting
I have tried and it is working fine. In addition, you just need to add customer parameter so that it will process base on the customer.