In October 2008, I have started an ambitious series of posts on this blog called – Spreadcheats. These are little tricks, nuggets, tutorials on using Excel that would make anyone a spreadsheet guru.
The spreadcheats series has been wildly successful. I am compiling all this useful information and articles in to one big post so that anyone can follow the links and become good in Excel. Read on,
[Note: This is not for beginners. If you know what a formula is, you would enjoy this 31 articles]
1: Insert Line Breaks in a Cell
Press ALT+Enter keys in a cell to make a new line inside the cell. [Read this]
2: Select all cells in a range
Use these keyboard shortcuts to select all the cells in a range or group. You can find 90 more shortcuts on that page. [Read this]
3: Using Mouse in Excel
Many of us know at few keyboard shortcuts. But what about mouse short-cuts? Read this post to learn interesting mouse shortcuts that can boost your productivity. [Read this]
4: Using Mouse in Excel – Part 2
In the second part of Mouse shortcuts, we explore double click tricks in Excel. [Read this]
5: Save time by using chart templates
In this spreadcheat, learn how to make your own chart templates and re-use them to save time. [Read this]
6: Make ToC (Table of Contents) in Excel – and other tricks
We all run in to large excel workbooks one time or other. Read this post to find out how you can manage when you have a large file. [Read this]
7: How to print spreadsheets one just one page?
Use the little trick in print settings to print any worksheet on just one page. [Read this]
8: Write better formulas by knowing the difference between relative and absolute references
Quick, what is the difference between A1 and $A$1? If you said 2 dollars, you are the right person to read this article. Learning the differences and usages of various reference types in Excel is important if you want to write better and simpler formulas. [Read this]
9: Remove duplicate items using formulas
Learn how to remove duplicates, identify unique values etc. using formulas in this article. [Read this]
10: Introduction to VLOOKUP Formula (and MATCH, OFFSET Formulas)
VLOOKUP remains one of the most important and very useful formulas in Excel. Learn how to write vlookup formulas by reading this article. [Read this]
11: Introduction to 3D References in Excel (a tutorial on Employee Satisfaction Surveys in Excel)
In this tutorial, we will explore a feature called 3D References in Excel and build an employee satisfaction survey form in Excel. [Read this]
12: Introduction to SUMPRODUCT formula
Learn how to use SUMPRODUCT to find sum of values that meet more than one condition. [Read this]
13: Introduction to ROWS and COLUMNS formulas
One of my recent favorites, ROWS() formula is very useful to generate sequential numbers in Excel. [Read this]
14: Calculate Moving Average in Excel
Use excel formulas and relative references to calculate moving average from your data. [Read this]
15: Introduction to FREQUENCY formula
We use FREQUENCY formula in Excel to generate statistical distribution of a set of values in this example. [Read this]
16: How to understand and fix excel formula errors
If you are ever perplexed by #N/A, #NAME! and said #$#@ to excel, this is the article for you. Read it to learn what these errors actually mean and how to fix them. [Read this]
17: Quick tip to Debug Complex Excel Formulas
Use Function key F9 to debug lengthy and complex excel formulas. Select a portion of the formula and press F9 to instantly evaluate that portion and see the result. Read this article to find out how to use this trick. [Read this]
18: Use Find / Replace tool to change formulas
Learn how to use Find / Replace tool in Excel to quickly edit formulas and change them. [Read this]
19: Introduction to COUNTIF and SUMIF Formulas
COUNTIF and SUMIF are very simple yet very powerful formula tools for anyone using Excel. In this article, explore these formulas and learn to use them. [Read this]
20: Introduction to Array Formulas in Excel
Array formula is like a mega formula that would work on an entire range of cells and return another range of cells. They are useful for scenarios where the output we need is not one value but a set of values. In this introductory example, learn how to write your first array formula. [Read this]
21: Introduction to Excel Conditional Formatting
Excel conditional formatting is your way of telling excel to highlight / change formatting of cells that meet certain criteria. This is a good way to draw attention to few points from a large table. Learn how to use Excel CF in this introductory article. [Read this]
22: Introduction to Excel Camera Tool
In this article, learn about Excel Camera (or Snapshot) tool which is useful for making a live snapshot of a range of cells. [Read this]
23: Introduction to Excel Pivot Tables
Pivot tables are a powerful way to analyze and report your data. In this introductory post, you will find all the basics of pivot tables and learn some tricks. [Read this]
24: Introduction to Excel Goal Seek
Goal Seek is opposite of formulas. In formulas we tell excel a bunch of values and excel finds the result. In goal seek, we tell excel what the result should and excel tells us what kind of parameters should be given. This is useful to find, for eg. Your retirement nest egg value … [Read this]
25: Introduction to Combination Charts in Excel
Learn how to combine 2 different chart types in to one chart in this article. [Read this]
26: Make a Dynamic / Interactive Chart using Data Filters
Do you know that we can use data filters to filter charts as well as data? Well, in this article, you can learn a powerful yet simple trick to make a dynamic chart in Excel using data filters alone. [Read this]
27: Make a Dynamic / Interactive Chart using INDEX Formula
Learn how to set up a dynamic or interactive chart using INDEX formula and Camera tool in Excel. [Read this]
28: Make Collapsible Charts using Group – Outline Tools
We can collapse / expand charts using the group and outline tools in Excel. Learn how to set up such a collapsible chart in Excel. [Read this]
29: Showing Chart Labels in Different Colors – Charting Tricks
Learn how to use custom cell formatting codes to show chart labels in different colors based on a criteria. [Read this]
30: Advanced Data Validation Tricks in Excel – Part 1
In part 1 of excel data validation tricks, we will learn how to use excel formulas to control the way data validation works. [Read this]
31: Advanced Data Validation Tricks in Excel – Part 2
In part 2 of data validation tricks, we will learn how to prevent duplicate data entry using data validation formulas. [Read this]
Happy learning 🙂
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!!!!!