ช่วยหน่อยครับ อ.ที่ปรึกษาให้แก้โปรเจคติดแค่นี้ครับคิดไม่ออกครับ 1.สินค้าขายดี 2.สรุปยอดรายเดือน 3.ราคาปรับเปลี่ยน (VB.NET + ACCESS)

  Me.....ชื่อตาราง......BindingSource.Filter = String.Format("D_DATE >= #{0:M/dd/yyyy}# AND D_DATE <= #{1:M/dd/yyyy}#", DateTimePicker1.Value, DateTimePicker2.Value)

SELECT	ITEM, DESCRIPTION , COST, PRICE FROM HR_ITEM_MST 
SELECT	ITEM
		,DESCRIPTION
		, COST
		, PRICE
		,((PRICE - COST) * 100)/PRICE [MARGIN]
FROM	HR_ITEM_MST
WHERE	((PRICE - COST) * 100)/PRICE >= 30
ORDER BY MARGIN DESC
SELECT	ITEM
		,DESCRIPTION
		,AVG(COST)		[COST]
		,AVG(PRICE)		[PRICE]
		,AVG(((PRICE - COST) * 100)/PRICE) [MARGIN]
FROM HR_ITEM_MST
GROUP BY ITEM,DESCRIPTION
HAVING ((AVG(PRICE) - AVG(COST)) * 100)/AVG(PRICE) >= 30
ORDER BY MARGIN DESC

with cte_rank as 
(
select 
ProductID,
sum(price) as #total,
DENSE_RANK() over (order by sum(price) desc) #Rank
from Table group by ProductID
)
select * from cte_rank where #rank between 1 and 5

select * from table where dateOrder between '' and ''

 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim str_ As String = TextBox1.Text
        If str_.ToString.IndexOf(".") = True Then
            MsgBox("OK")
        Else
            MsgBox("Error")
        End If
    End Sub

SELECT		TOP(5) ITEM, COUNT(ITEM) [TIME] , AVG(COST) [COST] , AVG(PRICE)  [PRICE]
FROM		HR_ITEM_MST
GROUP BY	ITEM
ORDER BY	COUNT(ITEM) DESC

SELECT		ITEM, SUM(QTY) , SUM(QTY * COST) [COST] , SUM(QTY * PRICE)  [PRICE]
FROM		HR_ITEM_MST
WHERE		CREATEDATE BETWEEN '2019-05-01 00:00:00' AND '2019-05-31 23:59:59' 
GROUP BY	ITEM

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress

    '97 - 122 = Ascii codes for simple letters
    '65 - 90  = Ascii codes for capital letters
    '48 - 57  = Ascii codes for numbers

    If Asc(e.KeyChar) <> 8 Then
        If Asc(e.KeyChar) < 48 Or Asc(e.KeyChar) > 57 Then
            e.Handled = True
        End If
    End If

End Sub

SELECT	ITEM
		,DESCRIPTION
		, COST
		, PRICE
		,((PRICE - COST) * 100)/PRICE [MARGIN]
FROM	HR_ITEM_MST
WHERE	((PRICE - COST) * 100)/PRICE <= 30
ORDER BY MARGIN DESC

    Dim sql As String = "SELECT TOP 4  * FROM Table WHERE DATE = '" & "date" & "'ORDER by Item"