How to save calculated values in MS Access

Question

I have a textbox in a form that I created.

I want to add an expression in the textbox\'s Control Source property. I also want to bind the textbox to a field in the tabl

Answer 1

If you have a text box named txtMy_field which is bound to a field named My_field in your form's record source, you could use the form's on current event to load the sum of those other two numbers into txtMy_field.

If you don't want to over-ride existing values stored in My_field ...

If IsNull(Me.txtMy_field) = True Then
    Me.txtMy_field = Number1 + Number2
End If

If you do want to over-ride existing values stored in My_field, eliminate the IsNull() condition.

Me.txtMy_field = Number1 + Number2

If Number1 and Number2 are from other controls on your form, you could also use their after update events to update txtMy_field value on demand.

However, I'm unsure how well I understand your question. These are only general suggestions and I hope they point you to something useful. Incidentally, if those two numbers come from two different forms (as in one of your previous questions) and you intend to display and store their sum via a third form, this could be more challenging than it appears from this question.