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
In the part 5 of our VBA Crash Course, let me share you my tips for mastering Excel VBA.
A warning before jumping in to the tips: I am not a VBA expert. I am a learner, just like you. I find VBA quite interesting language to learn and explore. These tips are based on what I have learned writing VBA (and VB code) in the last 12 years.
Tips for using & mastering VBA in short term:
#1 Think Thru before Coding
The best way to solve even a very complex problem is to think thru. Next time, when you are about to automate that report or clean some imported data using VBA, just write the logic down on a paper. See and understand various aspects of the problem. The solution becomes clear to you. It has worked for me and it works for you too.
Related: Building your First VBA Application using Excel
#2 Use the Recorder
Excel’s built in Macro recorder is a great way to learn about new objects and ways to deal with them. I use it all the time to record parts of my code and then customize the output. Just keep in mind that macro recorder does not produce the best or complete code all the time. But it gives you a damn good idea about how to write code for a set of actions.
Related: Introduction to Excel VBA & Writing your First Macro
#3 Use Immediate Window
Excel VBE has a powerful feature called as Immediate window. Think of this like a sandbox. You can write almost any VBA statements here and get quick results. For example, Open VBE (ALT+F11 in Excel) and go to Immediate window.
- Type ?Activecell.Value
- Press Enter
- And you will see the current cell’s value printed in immediate window
Here is a quick demo of immediate window.
#4 Debug.Print is your Friend
There are 3 things you cannot avoid in life
- your 2 year old daughter thinking it would be fun to throw a stone on your car
- your baby boy running and sitting in your lap suddenly making the hot coffee spill on you
- and of course bugs in your code
Bug is a fancy name given to the situation when your code is not doing what it is supposed to do.
But why?!? Well, we don’t know why unless we examine. And this is where Debug.Print can come handy. In below example, you would see the values of all tasks in the immediate window as your program runs.
#5 There is a method for that!
Just like Apple says There is an App for that!, may be Microsoft should say There is a Method for that! about VBA. I say this because VBA comes with a lot of methods and functions to do lots of things. If you are thinking of writing your own code to reverse some text, split something based on a delimiter, find the intersection of 2 ranges or run something after 10 seconds, may be you should before writing your code. Because, my dear, there is a method for that.
Whenever you feel like you are writing code for a problem that is already solved several times, chances are there is some built-in method or object for that. So just search.
Tips for Using & Mastering VBA in Long-term
While the above tips are good for solving your immediate problems, we should always aim for continuous improvement. Here are my top tips for keeping your VBA in shape.
#6 Break Your Work in to Smaller Chunks
No matter how complex your work situation or problem might be, chances are, it is made up of several smaller problems. So break things in to smaller chunks. This coding technique is called as modularization. Modularization has several advantages:
- Reuse: Once you break a big program to smaller parts, you can reuse a smaller part in several places or in other projects.
- Testable: Smaller code fragments are easy to test and debug.
- Maintainable: You can maintain smaller parts easily. You can upgrade them once you get a better version of Excel without breaking much.
#7 Build Iteratively
Rome is not built in one day, so is your buildRome() macro. Whenever you are attempting to automate a whole department’s work, take a step back and see what is the smallest (but most useful) feature you can have. Implement it and then add new features iteratively. That way, your turn-around time is improved, you look pretty in front of your boss and you feel in control of things.
Iterative development also lets you stop whenever you want and you would still have some working piece of code.
#8 Keep a Good Reference Handy
If you are going to use VBA quite often, then invest in a good reference. I suggest John Walkenbach’s Excel 2010 Power Programming if you are looking for one. Good reference books have lots of information and tips buried in them. For example, I keep Excel 2010 Power Programming book on my desk all the time and refer to it whenever I feel like not doing any work. I always learn something new.
#9 Take up Challenges
“Computers are like bicycles for our mind” said Steve Jobs. I am not sure if hours I put on facebook, twitter and gmail are keeping my mind fit. But any time I invest on programming is worth every second. I feel very sharp, excited and stoked when I solve a tricky problem using a computer program (be it VBA, an Excel Formula or php or anything else).
I think if you want to be good in VBA or Excel, then take up challenging work. Try to automate a report that you (or your team) produce using VBA, Try to simplify a formula or improve a chart.
If you are looking for fresh challenges, then look at our forums. We get dozens of interesting questions everyday.
#10 Use VBA only when you need it
Once you start learning VBA, it is natural to feel excited about the possibilities you have. But keep in mind that overusing it can complicate your work.
My suggestion: Use Excel’s native features as much as possible. Excel has several built in features to solve various day to day problems (conditional formatting, pivot tables, formulas, data validation, form controls to name a few). Only when you feel that there is no easy way to use Excel alone to solve a problem, go for VBA.
Example: Recently, I showed you all how to split text on new line using VBA. I did that because I thought there was no way to do it using Excel’s built in text-to-columns utility. Well, I was wrong. As Debra proved in the comments,
Chandoo, if you want to do this in the Text To Columns dialog box,
Select Delimited, then check “Other”
In the box beside Other, press the Alt key, and type (using the number keypad): 0010That should separate the text on the line break character.
So if you feel like there is no way to do something in Excel without resorting to VBA, well, just keep looking, because there might be a way.
What are your Tips for Learning & Mastering VBA?
Its your turn now. What are your top tips for mastering VBA? Please share using comments because I and many of our readers want to learn. Go ahead and post.
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Thanks
This post concludes our series on VBA Crash Course. I hope you enjoyed these 5 articles and learned something new. I really enjoyed writing this series. Thank you so much for your comments and support.
For more about VBA & Macros, consider enrolling in our online 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!!!!!