how to fix invalid use of null ? (1 Viewer)

[Dlovan-IT]

hello every one

i make the database for the fast food place , i have problem with the listbox , in the main form when opening you see all the tables of the restaurant for right know i active table 1 and table 2 , when click on the table it should be display all the item but the problem when i click on the table say "invalid use of null" i don't no what is problem please check my database in the attachment


regards

 

[Chungalin]

In frmSell:

Private Sub Form_Load()
List11.RowSource = "select * from table1 where tableno=" + "'" + Text9 + "'"
End Sub

Text9 (unbound textbox, labeled as "Table number") is Null and that causes the error.

When you click on table button...

Private Sub com1_Click()
DoCmd.OpenForm "frmSell"
Forms!frmSell!Text9.Value = com1.Caption
End Sub

...frmSell’s Form_Load executes before you assign a value to Text9, so at that point it’s still Null.

I can propose you to use OpenArgs argument in OpenForm to pass the table number to frmSell.

 

[Dlovan-IT]

thanks @Chungalin for your reply , can you explain me how to use OpenArgs argument to pass the table number ? or can you do it for me , so that to know me how you do it

 

[Chungalin]

I’m telling you where to fish, but you’re asking me for the fish...

In code window, move the cursor over DoCmd.OpenForm and press F1. Read what OpenArgs is and then click on OpenArgs help page, there’s a sample code too!

Private Sub com1_Click()
  DoCmd.OpenForm "frmSell", , , , , com1.Caption
End Sub

Sub Form_Open(Cancel As Integer)
  If Not IsNull(OpenArgs) Then
    Text9.Value = OpenArgs
    List11.RowSource = "select * from table1 where tableno=" + "'" + Text9 + "'"
  End If
End Sub

 

[Dlovan-IT]

thanks dear for take me the fish

but you know when i doing the openargs the second form was not opening ! are you testing it ? it is better pass the parameter and open form

 

[Chungalin]

This happens when one just copies+pastes without understanding it.

In DoCmd.OpenForm call there’re 5 commas. Should be 6.

 

[Dlovan-IT]

yeah you are right dear , i trying too much to knowing that , wonderful my problem was solved