Date comparisons

Date comparisons

• astrocrep

  tattoo wrote:

  I have an access database that has a column of dates. As I display these records, I want to compare the date in that field to the current date and if it is less than today, I want to alter a seperate label to indicate that the item on the record is expired. I'm having a problem comparing the date in the db to the current date. the data from my db is being displayed in a text box, txtexpirydate. When I try to get the value of that as val(txtexpirydate.text) I get an error. that's even before trying to compare to anything. can someone please point me in the right direction. thanks tattoo

  Hi tattoo,

  Here is a simple example that will only compare the date of today to a date you place in a variable. The variable can come from a textbox or directly from you database. I am including an example of how to use it with a textbox. The CDate in the function is the key part; this operator converts the variable to a simple date format of M/D/YYYY. Do be aware this is setup for US date formats and will not accept words as the month; so if you were to enter Sept. 17, 2006 or 17/9/06 then it will produce an error; the date would need to be entered as 09/17/06, or 9/17/06, or 9/17/2006, etc...

  Public Function IsDateToday(ByVal DateToCompare As Date) As Boolean

  Dim dtToday, dtCompareDate As Date
  dtToday = CDate(Today)
  dtCompareDate = CDate(DateToCompare)
  If dtCompareDate = dtToday Then IsDateToday = True
  Return IsDateToday

  End Function

  Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

  Dim blnResults As Boolean
  Dim dtexpirydate As Date
  dtexpirydate = txtexpirydate.Text
  blnResults = IsDateToday(dtexpirydate)
  If blnResults = True Then
  MessageBox.Show("Date is today.")
  Else
  MessageBox.Show("Date is NOT today.")
  End If

  End Sub

  I hope this helps you.

  Thank you,

  James

  
  
  

• somegai

  get the date/time object from the database then try to do a TryParse to see if it can be converted to a datetime object.....

  Dim theResult as new DateTime()

  If DateTime.TryParse(Me.txtexpirydate, ByRef theResult) then

  'successfully parsed datetime, result stored in theResult - now do your thing

  end if

  does this help

  
  
  

• Marcin Książek

  you are better to use TryParse rather than a direct convert to (CDate) as well as the added value of less code. I guess there are many ways for a solution but tryparse would be the better option and best practice

  
  
  
• Date comparisons