Weekly Data show - vb.net

Question

Please any one help me, I just making a micro finance type software, there was a problem I want to show every week data from access database to vb.net datagrid view but don't work my code,
I insert EntryDate Savings Entry Lable Date (lblSavingsEntryDate.Text = Date.Now.ToString("dd/MM/yyyy"))
Here is my Code
Private Sub btnBalanceWeekly_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBalanceWeekly.Click
Dim Sunday = DateTime.Now.AddDays((Today.DayOfWeek - DayOfWeek.Sunday) * -1).ToString("dd/MM/yyyy")
Dim todate = DateTime.Now.AddDays(0).ToString("dd/MM/yyyy")
Try
Dim sqlstr1 As String
sqlstr1 = "SELECT * FROM Receivedtbl WHERE EntryDate BETWEEN '" + Sunday + "' And '" + todate + "'"
Dim da As New OleDbDataAdapter(sqlstr1, conn2)
Dim dt As New DataTable("Receivedtbl")
da.Fill(dt)
dgvBalanceSavings.DataSource = dt
Catch ex As Exception
MessageBox.Show(ex.Message)
Finally
conn2.Close()
Me.BalanceTotalSeavings()
Me.BalanceGrpReceived()
Me.BalanceCusReceived()
End Try
End Sub
Please Help... How can show data in every week.

Answer 1

It's much more secure and safer way using Parameters (DataAdapter will convert in proper way date, datetime format in sql) instead converting date into string, especially because different date formats and avoiding sql injection.
Bellow is example with using Parameters in, let say, source format (in this case date data type) :
Private Sub btnBalanceWeekly_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBalanceWeekly.Click
Dim Sunday = DateTime.Now.AddDays((Today.DayOfWeek - DayOfWeek.Sunday) * -1)
Dim todate = DateTime.Now.AddDays(0)
Try
Dim sqlstr1 As String
sqlstr1 = "SELECT * FROM Receivedtbl WHERE EntryDate BETWEEN #sunday AND #todate;"
Dim da As New OleDbDataAdapter(sqlstr1, conn2)
da.SelectCommand.Parameters.AddWithValue("#sunday", Sunday)
da.SelectCommand.Parameters.AddWithValue("#todate", todate)
Dim dt As New DataTable("Receivedtbl")
da.Fill(dt)
dgvBalanceSavings.DataSource = dt
Catch ex As Exception
MessageBox.Show(ex.Message)
Finally
conn2.Close()
Me.BalanceTotalSeavings()
Me.BalanceGrpReceived()
Me.BalanceCusReceived()
End Try
End Sub
By this way You don't have to worry about date format conversion.

Answer 2

You trying to compare a date (string date) as "dd/MM/yyyy" format and you have a big problem because your query will be like this in runtime :
WHERE EntryDate BETWEEN '11/02/2018' And '12/02/2018'
Result : Tons of strings are between these dates
For example : '11/02/2018','11/03/2018','11/04/2018', even another year like '11/02/2019'
In string compare, early characters always compare first and they are more important in compare system (in this case your 4 chars for year have less priority than month and even day)
Solution :
Use this format for saving your date :
.ToString("yyyy/MM/dd")
So your code should be like this :
Private Sub btnBalanceWeekly_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBalanceWeekly.Click
Dim Sunday = DateTime.Now.AddDays((Today.DayOfWeek - DayOfWeek.Sunday) * -1).ToString("yyyy/MM/dd")
Dim todate = DateTime.Now.AddDays(0).ToString("yyyy/MM/dd")
Try
Dim sqlstr1 As String
sqlstr1 = "SELECT * FROM Receivedtbl WHERE EntryDate BETWEEN '" + Sunday + "' And '" + todate + "'"
Dim da As New OleDbDataAdapter(sqlstr1, conn2)
Dim dt As New DataTable("Receivedtbl")
da.Fill(dt)
dgvBalanceSavings.DataSource = dt
Catch ex As Exception
MessageBox.Show(ex.Message)
Finally
conn2.Close()
Me.BalanceTotalSeavings()
Me.BalanceGrpReceived()
Me.BalanceCusReceived()
End Try
End Sub
But remember you need save your date string with this format too (old dates which already saved in your database)

Answer 3

First and forever turn on Option Strict. Compile Time errors - good, you can fix them. Runtime errors bad, you might not catch them.
Add two DateTimePicker controls to your form and appropriate labels. There are all kinds of properties you can set if the defaults don't suit you.
The following code shows you how to use parameters with your SQL strings. This not only saves you headaches formating your string but could save your database from malicious input.
Private Sub GetSavings()
Dim da As New OleDbDataAdapter
Dim strSQL As String = "SELECT * FROM Receivedtbl WHERE EntryDate BETWEEN #FromDate And #ToDate;"
Dim FromDate As Date = DateTimePicker1.Value.Date
Dim ToDate As Date = DateTimePicker2.Value.Date
If FromDate >= ToDate Then
MessageBox.Show("From date must be earlier than To date.")
Exit Sub
End If
Dim cmd As New OleDbCommand With {
.Connection = conn2,
.CommandType = CommandType.Text,
.CommandText = strSQL}
'Access cares not about the parameter names but about there order
cmd.Parameters.Add("#FromDate", OleDbType.Date).Value = FromDate
cmd.Parameters.Add("#ToDate", OleDbType.Date).Value = ToDate
da.SelectCommand = cmd
'now continue with your .Fill code
End Sub