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Tag: unique items

Data Validation using an Unsorted column with Duplicate Entries as a Source List

Here is a typical scenario: We want to allow only one of the pre-defined customer names in our spreadsheet. We have listed down all the customers in column B and want excel to check against this list and validate the data. But there are 3 problems. (1) Our list is not sorted alphabetically (2) It contains duplicates and (3) The list comes from external source, so we can not remove duplicates and sort the list every time.

Now how can we set up a simple data validation list that would not repeat customer names and shows them in sorted order like this.

Read the rest of this guest post by Hui to learn how to use data validation in creative new ways.

Prevent Duplicate Data Entry using Cell Validations

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. But, do you know that you can use data validation in a multitude of ways to prevent users from entering wrong data?

Here is a practical application: Prevent users from entering duplicate values in a range of cells.

For eg. you are making an invoice. Wouldn’t it be cool if Excel prompted you when you enter a duplicate line item so that increase the item quantity instead of repeating it.

Count the number of unique values in a range [Quick Tip]

Here is an excel formula quick tip that can come handy when you need to count the number of unique values in a range of cells. Assuming we have a list of values in the range:B5:B15 and we want to know how many unique values are there,
you can use the almighty SUMPRODUCT formula like this: SUMPRODUCT(1/COUNTIF(B5:B15,B5:B15)).

Read the rest of this post to understand how the formula works. You can also find resources to work with duplicate values in excel.

Remove Duplicates [Quick Video Tip]

It is very surprising that so many of us are still not aware of this extremely powerful tool in Excel 2007. Just with a click of the button, you can remove all the duplicate values from a list / table. To remove duplicates, (1) Just select the list of values from which you want to remove duplicates (2) Go to Data ribbon (3) Hit the Remove Duplicates button (4) Bingo…