
This week many Excel bloggers are celebrating VLOOKUP week. So I wanted to chip in and give you a comprehensive guide to VLOOKUP & Other lookup formulas. Read on …,
What is VLOOKUP Formula & how to use it?
I tell my excel school students that learning VLOOKUP formulas will change your basic approach towards data. You will suddenly feel that you have discovered a superman cape in your attic. It is that awesome.
What does VLOOKUP really do?
Imagine you have a list of data and you want answer a question like, “How many sales did Jimmy make?”
VLOOKUP is one of the formulas you can use in this situation. VLOOKUP searches a list for a value in left most column and returns corresponding value from adjacent columns.

Read more – What is VLOOKUP formula and how to use it?
Introduction to VLOOKUP, MATCH & OFFSET formulas
VLOOKUP may not make you tall, rich and famous, but learning it can certainly give you wings. It makes you to connect two different tabular lists and saves a ton of time. In my opinion understanding VLOOKUP, OFFSET and MATCH worksheet formulas can transform you from normal excel user to a data processing beast.
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Read more – VLOOKUP, MATCH & OFFSET explained in plain English
How to do wildcard searches with VLOOKUP?
Often we need our lookup formulas to go wild. Not in the sense of go-wild-and-chomp-a-few-kilo-bytes-of-data sense. But wild like wild cards. For eg. In the below data, we may not remember the full name of sales person, but we know that her name starts with jac. Now how do you get the sales amount for that person?
You can use wildcard characters * and ? with VLOOKUP & several other Excel formulas.

Read more – Using wildcards with VLOOKUP formulas
Making VLOOKUPS dynamic with data validation
Sometimes we don’t know what we want. If this happens when I am in a bar, I usually order a cocktail. Just a mix of everything. The same will work in Excel too.
For eg. If you have lots of data, but the value you want to look up needs to change based on whims and fancies of your users, then you can resort to a cocktail. A mix of VLOOKUP with Drop down lists (Data validation).

Read more – Use data validation with VLOOKUP to lookup anything you want
How to lookup values to the left?
There is no argument that VLOOKUP is a beautiful & useful formula. But it suffers from one nagging limitation. It cannot go left.
Let me explain, Imagine you have data like below. Now, if you want to find-out who is the sales person who made $2,133 in sales, there is no way VLOOKUP can come to rescue. This is because, once you search a list using VLOOKUP, you can only return corresponding items from the column at right, not at left.

Read more – How to use INDEX + MATCH combination to fetch values from left
How to lookup based on multiple conditions?
Not always we want to lookup values based on one search parameter. For eg. Imagine you have data like below and you want to find how much sales Joseph made in January 2007 in North region for product “Fast car”? Read more to find how to solve this.
Read more – How to lookup based on multiple conditions?
How to get values from multiple columns with VLOOKUP?
VLOOKUP is great for extracting information from a huge data table based on what you are looking for. But what if you need to extract more than one column of information? For eg. Lets say you have salesperson’s name in left most column, and monthly sales figures in next columns, one for each month. Now, you want to find the total sales made by a given sales person. How do you go about it?
Read more – How to get values from multiple columns with VLOOKUP?
Using VLOOKUP formula with tables
Excel Tables, a newly introduced feature in Excel 2007 is a very powerful way to manage & work with tabular data. I really like tables feature and use them often. If you are new to tables, read up Introduction to Excel Tables. In this short video, understand how to use tables with VLOOKUP formulas.
Watch the video – Using VLOOKUP formula with tables
Doing 2 way lookups in Excel
So far we have seen what VLOOKUP formula is and how to put it to some nifty uses. Lets go one step further and learn how to do 2 Way Lookups.
What is a 2 Way Lookup?
Lookup is when you find a value in one column and get the corresponding element from other columns. 2 Way Lookup is when you lookup value at the interesection of a given row & column values.

Read more – 2 way lookup formula in Excel
Getting 2nd matching value from a list using VLOOKUP
We know that VLOOKUP formula is useful to fetch the first matching item from a list. So what would you do if you need 2nd (or 3rd etc.) matching item from a list?
Read more – Getting 2nd matching value using VLOOKUP
Range lookups in Excel
Here is a really tricky problem. Recently I was given a data set like this (shown below) and asked to find the position of lookup value in the list. The only glitch is that, instead of values, the lookup table contained lower and upper boundaries of the values. See the below illustration to understand the situation. In this case, how do you lookup?

Read more – Doing range lookups in Excel
6 VLOOKUP tips
Ok, you have learned how to write vlookup formulas. You have also seen some pretty interesting examples of it.
But how do you write better VLOOKUP formulas?
Read more – 6 VLOOKUP tips
FREE VLOOKUP cheat sheet – Download today
Please download free VLOOKUP formula cheat-sheet. This cheat-sheet is prepared by Cheater John specifically for our readers. I hope you enjoy the one page help on VLOOKUP.
Download FREE VLOOKUP cheat sheet
Your Favorite VLOOKUP Tips?
When I am working with data, not a day goes by without using some sort of lookup function. I use VLOOKUP, MATCH, INDEX, OFFSET, SUMIFS, SUMPRODUCT, GETPIVOTDATA in most of my dashboards & reports. These are easy to use once you understand the syntax and technique.
What about you? What are your favorite tips on VLOOKUP? How do you use lookup formulas? Please share using comments.
Want to Learn More Formulas? Get my VLOOKUP book
If you want to learn VLOOKUP and other Excel lookup functions, then consider getting my VLOOKUP book.
















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!!!!!