This article is part of our VBA Crash Course. Please read the rest of the articles in this series by clicking below links.
- What is VBA & Writing your First VBA Macro in Excel
- Understanding Variables, Conditions & Loops in VBA
- Using Cells, Ranges & Other Objects in your Macros
- Putting it all together – Your First VBA Application using Excel
- My Top 10 Tips for Mastering VBA & Excel Macros
Introduction to Excel VBA
Everyone has a language. My mother tongue is Telugu. But I also speak Hindi, English and Cutish (that is the language my 2 year old kids speak). You may be fluent in English, Spanish, French, German or Vietnamese.
Just like you and I, Excel has a language too, the one it can speak and understand. This language is called as VBA (Visual Basic for Applications).
When you tell instructions to Excel in this VBA language, Excel can do what you tell it. Thus enabling you to program Excel so that you can automate a boring report, format a big&ugly chart, clean-up some messy data or just play some random noises.
What is a Macro then?
A macro is nothing but a set of instructions you give Excel in the VBA language.
Writing Your First Macro
Note: If you are new computer programming, watch our Introduction to Programming Video before proceeding.
In order to write your first VBA program (or Macro), you need to know the language first. This is where Excel’s tape recorder will help us.
Tape Recorder?!?
Yes. Excel has a built-in tape recorder, that listens and records everything you do, in Excel’s own language, ie VBA.
Since we dont know any VBA, we will use this recorder to record our actions and then we will see recorded instructions (called as code in computer lingo) to understand how VBA looks like.
Our First VBA Macro – MakeMeRed()
Now that you understand some VBA jargon, lets move on and write our very first VBA Macro. The objective is simple. When we run this macro, it is going to color the currently selected cell with Red. Why red? Oh, red is pretty, bright and awesome – just like you.
This is how our macro is going to work when it is done.
6 steps to writing your first macro
If you do not see Developer ribbon, follow these instructions.
Excel 2007:
1. Click on Office button (top left)
2. Go to Excel Options
3. Go to Popular
4. Check “Show Developer Tab in Ribbon” (3rd Check box)
5. Click ok.
Excel 2010:
1. Click on File Menu (top left)
2. Go to Options
3. Select “Customize Ribbon”
4. Make sure “Developer tab” is checked in right side area
5. Click ok.
Step 1: Select any cell & start macro recorder
This is the easiest part. Just select any cell and go to Developer Ribbon & click on Record Macro button.
Step 2: Give a name to your Macro
Specify a name for your macro. I called mine MakeMeRed. You can choose whatever you want. Just make sure there are no spaces or special characters in the name (except underscore)
Click OK when done.
Step 3: Fill the current cell with red color
This is easy as eating pie. Just go to Home ribbon and fill red color in the current cell.
Step 4: Stop Recording
Now that you have done the only step in our macro, its time to stop Excel’s tape recorder. Go to Developer ribbon and hit “stop recording” button.
Step 5: Assign your Macro to a button
Now go to Insert ribbon and draw a nice rectangle. Then, put some text like “click me to fill red” in it.
Then right click on the rectangle shape and go to Assign Macro. And select the MakeMeRed macro from the list shown. Click ok.
Step 6: Go ahead and play with your first macro
That is all. Now, we have linked the rectangle shape to your macro. Whenever you click it, Excel would drop a bucket of red paint in the selected cell(s).
Go ahead and play with this little macro of ours.
Understanding the MakeMeRed Macro Code
Now that your first macro is working, lets peek behind the scenes and understand what VBA instructions are required to fill a cell with red.
To do this, right click on your current sheet name (bottom left) and click on View code option. (You can also press ALT+F11 to do the same).
This opens Visual Basic Editor – a place where you can view & edit various VBA instructions (macros, code) to get things done in Excel.
Understanding the Visual Basic Editor:
Before understanding the MakeMeRed macro, we need to be familiar with VBE (Visual Basic Editor). See this drawing to understand it.
Viewing the VBA behind MakeMeRed
- Select Module 1 from left side area of VBE (called as Project Explorer).
- Double click on it to open it in Editor Area (top right, big white rectangle)
- You can see the VBA Code behind MakeMeRed
If you have followed the instructions above, your code should look like this:
Sub MakeMeRed()
'
' MakeMeRed Macro
'
With Selection.Interior
.Pattern = xlSolid
.PatternColorIndex = xlAutomatic
.Color = 192
.TintAndShade = 0
.PatternTintAndShade = 0
End With
End Sub
So much for a simple red paint!!!
Well, what can I say, Excel is rather verbose when it is recording.
Understanding the MakeMeRed VBA Code
Lets go thru the entire Macro code one line at a time.
- Sub MakeMeRed(): This line tells Excel that we are writing a new set of instructions. The word SUB indicates that the following lines of VBA are a sub-procedure (or sub-routine). Which in computer lingo means, a group of related instructions meant to be followed together to do something meaningful. The Sub-procedure ends when Excel sees the phrase “End Sub”
- Lines starting with a single quote (‘): These lines are comments. Excel will ignore anything you write after a single quote. These are meant for your understanding.
- With Selection.Interior: While filling a cell with Red color may seem like one step for you and I, it is in fact a lot of steps for your computer. And whenever you need to do a lot of operations on the same thing (in this case, selected cell), it is better to bunch all of them. This is where the WITH statement comes in to picture. When Excel sees With Seletion.Interior, Excel is going to think, “ok, I am going to do all the next operations on Selected Cell’s Interior until I see End With line“
- Lines starting with .: These are the lines that tell Excel to format the cell’s interior. In this case, the most important line is .Color = 192 which is telling Excel to fill Red color in the selected cell.
- End With: This marks the end of With block.
- End Sub: This marks the end of our little macro named MakeMeRed().
Few Tips to understand this macro better:
Once you are examining the macro code, here are a few ways to learn better.
- Change something: You can change almost any line of the macro to see what happens. For example, change .color = 192 to .color = 62 and save. Then come back to Excel and run your macro to see what happens.
- Delete something: You can remove some of the lines in the macro to see what happens. Remove the line .PatternColorIndex = xlAutomatic and run again to see what happens.
Download Example Workbook to learn VBA
Click here to download the example workbook with MakeMeRed Macro.
Excel 2003 Compatible Version here.
Play with the code & understand this better.
What Next – Understanding Variables, Conditions & Loops
In the part 2 of this tutorial, Learn about variables, conditions & loops – basic programming structures of VBA.
Do you write VBA Code? Share your experience?
Thanks to my college education & job experience. I am trained to be a programmer. So I find VBA quite intuitive and easy to use. But that may not be the case for many of you who latch on to VBA without any formal education.
I would like to know how you learn VBA and what experiences you had when you wrote that first macro. Please share using comments.
Join Our VBA Classes
We run an online VBA (Macros) Class to make you awesome. This class offers 20+ hours of video content on all aspects of VBA – right from basics to advanced stuff. You can watch the lessons anytime and learn at your own pace. Each lesson offers a download workbook with sample code. If you are interested to learn VBA and become a master in it, please consider joining this course.
42 Responses to “Prevent Duplicate Data Entry using Cell Validations”
Hi Chandoo, I need you help in the following problem.
I'm trying to get a direccion from a found result. With this dirreccion I will want the before cell value. For example, If result of a find is 38 localized in cell $C$2, I need to get previus value (cell $B$2 ), maybe Andrés.
Do you know some way to do that?
Thank you for you help.
Hi Chandoo
Thanks for this. One thing though: In my pre-2007 version of Excel, the COUNTIF function doesn't recognise a semicolon (;), but requires a comma.
Is the semicolon an Excel 2007 thing?
Jair... I am not sure I understand what you want. what do you mean by Dirreccion?
@Lincoln: I am sorry, often I forget that I am using European version of excel where the delimiter is ; instead of ,. I have corrected the formula now.
Thanks for this nice tip, i used to do a find all after filling every new items which was cumbersome.
Do you know a way to extend this validation search to other tabs/sheets ?
Thanks for you attention. I'm trying to get of value continue from a found value. Let me show a example:
Name Years
John 35
Maria 28
Teresa 32
If I search the max years, the result is 35, but I need that result to be John. Do you know how I can do it?
@Subbu.. you can easily extend the validation to other sheets by pasting the data validations. See the latest article here: http://chandoo.org/wp/2009/10/28/copy-data-validations/
@Jair.. you can use the large() or small() formulas to do this. for eg. =index(A1:A3,large(B1:B3,1)) will get you the name of the person with highest "years". More help here: http://chandoo.org/excel-formulas/large.html
Hi, I don't know if I'm using bad the formula or its performance is diferent for my Office version. Large() formula return the value in the cell, in my example 35. The index() formula use a range, row and column. I'm using the large() as number of row, and it is bad because into the range don't have row 35. This is my perception. What do you think?
Hi, I going to prove, with this solution by JLD http://jldexcelsp.blogspot.com/2008/07/extraer-direccion-de-celda-en-matriz.html
Hello,
I am trying to attempt data validation in Excel Mobile, but the DV tool isnt available. I want to prevent duplicates is all, any advice on acheiving this in Excel Mobile? Thanks..
@Jair... my french aint that good. it starts at "merci" and ends at "beau coup".
Anyhow, you need to merge the large with vlookup to do this. I am not sure if you have solved the problem. Otherwise let me know with details and I can write the formula in comments.
@Chad... I have never used excel mobile, so I have no idea. May be they have not implemented data validations in excel mobile.
Any excel mobile users out there?
Hi Chandoo, the proposed solution by JlD is interesting. He created a macro to get values when the matrix is not one dimensional, how on my problem. This fuction for me.
I would like to share you my work, how can I upload?
@Jair.. sorry for such a delayed reply.. you can upload the files to skydrive and link them here. Or you can email them to me at chandoo.d @ gmail.com and I will upload them somewhere. But it could take forever if you email files to me as I am a bit lazy.
[...] Day 31: Advanced Data Validation Tricks in Excel – Part 2 [...]
Hi,
Can you help me in Microstrategy?
Br,
Moin
really wonderful article. I feel it is implementing Primary Key concept into spreadsheets.
Hi article on data validation. Excel is a very versatile platform to work with and we use it for all kinds of data tabulation. In fact this must have been the most rudimentary data management tools I must have worked with and knowing such tips only adds functuionality to our user experience. Great article. looking forawrd to read more.
Hi Chandoo,
Thanks for such a nice idea.
I tried copy paste the data into the validated area, but the pop-up msg (warning msg) doesn't came. Is it something that we need to update the data manually each time,.
Do we have any option where we can bulk upload the number and it throws a warning message that the data already exits and do we want to continue with this ?
Please do reply me.
Thank you.
Regards,
Vasanth.
It was really useful chandoo...thanks a lot...
Tried this in excel 2010 and it did not work?
Could the newer excel have changed that much?
@Leo
It works fine in Excel 2010
The formula used above =COUNTIF($B$4:$B$11,B4)<=1
only applies to the range B4:B11
Did you adjust the range to your data?
This page helped me accurately to find solution of my question. thanx
we want to prevent duplicate entries in three columns combined, using data validation, i.e. say, column A has first name and Column B has middle name, Column C has last name. the first name can be duplicate, middle name can be duplicate, last name can be duplicate, but not all three at the same time.
I want to prevent duplicate entries in three columns combine, using data validation, i.e. say, column A has first name and Column B has middle name, Column C has last name. the first name can be duplicate, middle name can be duplicate, last name can be duplicate, but not all three at the same time.
Hi, I've tried above validation method to prevent duplicate value from entering into the cells. It's work, when user key in the data into the selected range. However, it's not working when user copy-&-paste the info into the same range.
Please advice. Thanks.
Hi Chandoo,
Does it work in Excel 2007?
Please Reply
thanks chandoo........
it does not work when data is copy pasted...any solution for this??
hi i m shaloo and i want to know in excel if i write duplicate no.then it says or show about we are write duplicate no.
Hi Chandoo
I've tried using this with a Named Range, which is actually a column in a Table as DV wont accept a table reference, and it wont work.
Also tried using Offset to specify the Named Range, but that wont work either.
Is it possible to use Named Ranges with DV?
Thanks
Kris
I have tried the above formula on a table column. The Error box does not pop up, there is only the small ! next to the cell with the duplicate. The column I am working with is formulas that produce a date. Is the reason it doesn't work that the cells contain formulas rather than data?
The formula works but only if I enter data in cell above it. So for example, if I have "123" in B11 it does not allow me to enter "123" in B10, B9, B8, etc. But I can still enter "123" in B12. Please help! 🙂
Great tip.. thanks a lot
I have 21 years of experience working as data entry assistant. I constantly read several blogs to keep myself up-to-date with the advances in data entry profession. I really enjoyed this blog post. From my several years of experience, I agree with you 100% when you say, “ We all know that data validation is a very useful feature in Excel. You can use data validation to create a drop-down list in a cell and limit the values user can enter. ”
Keep blogging. I will come here again.
--data entry assistant
Hi,
This is really very helpful.
Thank you
how can i assign two validation on a single cell
one is for list validation (means the data should be from that range)
second i want to prevent them from repetition
how can i do this ?
P7 to P506 have GR# which are for list
i want to prevent C column to not to repeat and should be from the P column
@Junaid
Can you please post the question in the Chandoo.org Forums
http://forum.chandoo.org/
You have to register to be able to post questions
Please attach a file so that a specific answer can be delivered.
i made an account but there is no option available to post questions ??
where can i ??
@Jubaid
Goto http://forum.chandoo.org/
Goto Ask an Excel Question
Post New thread
Type your question
Attach a file
Please attach a file so that a specific answer can be delivered.
friend can any one tell me the formula
exname location qty
gaurav 1 1
rofan 2 5
sandeep 3 6
gaurav 4 3
rofan 5 4
sandeep 6 8
gaurav 7 9
If this is a data.
if i want a formula by which if i type gaurav then all the location and qty should be shown in a new page.
i had 5,00,000 sku so if i punch one name i can get the entire details
@Gaurav
Can you please post the question at the Chandoo.org Forums
http://forum.chandoo.org/
Please attach a sample file for a quicker more targeted response
IF(ISERROR(INDEX($B$3:$C$9,SMALL(IF($B$3:$B$9=$B$12,ROW($B$3:$B$9)-ROW($C$2)),ROW(A1:C1)),2)),"",INDEX($B$3:$C$9,SMALL(IF($B$3:$B$9=$B$12,ROW($B$3:$B$9)-ROW($C$2)),ROW(A1:C1)),2))
please explain
YOUR COUNTIF FORMULA IS REALLY HELPFUL AND WORKS. I TRIED SEVERAL SITES BUT THEIR FORMULA DOES NOT WORK. ONLY YOU HAVE GIVEN A RIGHT FORMULA!
THANK YOU!!!!!