Data validation problem

[Adamlearnexcel]

Dear everyone.

Please refer my attached document.
In the first column of my data. I want to key in product part number.
One part number will have several serial number, I will key in serial number at second column.
I want to make sure that only can key in same part number in the first column. when someone enter number is different from other number, system will tell him that only can enter one same number. how could I do this? using data validation?
PS:every time number is entered in first column can be different. but every time only allow same number in the first column.

[dogberry]

Hi

Dont think you will achieve that with Data Validation, looking at your sheet it is the same number all the time so why not use your autofil to have the cell already populated and no one has to enter anything in column A

Chris

[dogberry]

Hi

I stand corrected see attached file (by myself)


Chris

[6StringJazzer]

I am having trouble understanding your explanation but here's what I think is going on:

• The user starts with a blank form. They can enter any part number into A2.
• All subsequent part numbers must be the same as the one they entered into A2.

If that is correct, then you can apply data validation in A3:A50. Select Custom and use the formula

=$A$2

[Adamlearnexcel]

• The user starts with a blank form. They can enter any part number into A2.
• All subsequent part numbers must be the same as the one they entered into A2.

Yes, this is what i mean, but how come when I follow your step, I cannot enter same value in the following row?

[Adamlearnexcel]

Hi, Sir, how come I still can enter different numbers?

[6StringJazzer]

I'm sorry, I gave you the wrong formula. See attached for correction.

[6StringJazzer]

The way to enter this formula is to highlight the cells where you want to apply it starting with A3, then set data validation, Custom, using this formula:

=A3=$A$2

[Adamlearnexcel]

OK, I see, it worksl, thank you so much......