This is a guest post by Vijay, our in-house VBA Expert.
Often I have thought, if I could have write “Select EmployeeName From Sheet Where EmployeeID=123” and use this on my excel sheet, my life would be simpler. So today we will learn how to do this.
People spend a lot of time thinking whether to use Excel as their database or not. Eventually they start using Access or SQL Server etc.
Today we will learn how to use Excel as a Database and how to use SQL statements to get what we want.
Excel as a Database – Demo
We will learn how to build this:
Before we begin:
- The entire sheet (where the raw data has been stored) will be referred as one single database table by Excel. This is very important to understand.
- This has nothing related with the in-built Table (2007 and greater) / List (2003 and previous) feature of Excel.
- If you know SQL (Structured Query Language) your task becomes much easier.
Setting up Excel as Database
We need some raw data and we will utilize Customer Service Dashboard sample database here.
Let’s get started.
First we will design the structure of what all option we want to present for filtering the data, which you can see in the interface below.
Once the user clicks on Show Data we will use a SQL statement to filter-out the data as per the drop down options selected by the user and the put them in the table below.
We will also use another SQL statement to populate the top right hand side table for calls data when all the 3 drop downs have some options selected.
Adding Active-x data objects reference
We need to add a reference to the Microsoft ActiveX Data Objects Library to be able to use the worksheet as a database table. You can do this from Visual Basic Editor > Tools.
I usually select the most recent version, however if you are developing a product it will be best suited if you are familiar with the operating system and office version used by the end-user’s system and accordingly select the best version available.
Opening Excel as a Database
Once this is done we need to hit the road with some VBA code.
Public Sub OpenDB()
If cnn.State = adStateOpen Then cnn.Close
cnn.ConnectionString = "Driver={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)};DBQ=" & _
ActiveWorkbook.Path & Application.PathSeparator & ActiveWorkbook.Name
cnn.Open
End Sub
The above procedure is the heart of this post, this is where we define how to use the current Excel workbook as our database.
cnn.ConnectionString = "Driver={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)};DBQ=" & _
ActiveWorkbook.Path & Application.PathSeparator & ActiveWorkbook.Name
On this line, we define all the possible file extensions that we are allowed to create an Excel Workbook and then use as our database.
Let’s understand the code module
When you click on the Update Drop Downs button, the VBA code uses the “Data” worksheet as a table and then finds unique values for Products, Region and Customer Types and then populates them as ListItems for the ComboBox controls.
Example for Products drop down
strSQL = "Select Distinct [Product] From [data$] Order by [Product]"
closeRS
OpenDB
cmbProducts.Clear
rs.Open strSQL, cnn, adOpenKeyset, adLockOptimistic
If rs.RecordCount > 0 Then
Do While Not rs.EOF
cmbProducts.AddItem rs.Fields(0)
rs.MoveNext
Loop
Else
MsgBox "I was not able to find any unique Products.", vbCritical + vbOKOnly
Exit Sub
End If
What is important to notice here is how the Table and Fields have been identified using square brackets unlike traditional SQL where we just provide the name, also the table name has to be suffixed with a $ symbol at the end.
As I have suggested earlier, one entire sheet will be treated as one single table, so if you have multiple datasets that were currently organized within one sheet you may have to create multiple sheets to store that data to be able to use them as tables. This would also make maintenance of data easier.
Using Excel SQL to consolidate two sheets in to one
Many people ask, how to consolidate 2 or more sheets which have the similar data. Well I would have adopted this method and wrote a simple query as below.
SELECT ID, FirstName, MiddleName, LastName, Age, DOB From [Table1$]
UNION ALL
SELECT ID, FirstName, MiddleName, LastName, Age, DOB From [Table2$]
This would allow me to use both the sheets as one table and fetch all of my data into a new sheet.
Download Excel As Database Demo File
Click here to download the demo file & use it to understand this technique.
Do you use Excel as a database?
Do you also user Excel as your database? If yes please put in the comment below how do you use the same and what has been your experience. Leave a comment.
More on VBA & Macros
If you are new to VBA, Excel macros, go thru these links to learn more.
Join our VBA Classes
If you want to learn how to develop applications like these and more, please consider joining our VBA Classes. It is a step-by-step program designed to teach you all concepts of VBA so that you can automate & simplify your work.
Click here to learn more about VBA Classes & join us.
About Vijay
Vijay (many of you know him from VBA Classes), joined chandoo.org full-time this February. He will be writing more often on using VBA, data analysis on our blog. Also, Vijay will be helping us with consulting & training programs. You can email Vijay at sharma.vijay1 @ gmail.com. If you like this post, say thanks to Vijay.
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!!!!!