Apply data validation to the whole column

Hello I need to apply the data validation rule to the whole data in column not only the first 255 cells how can I apply the formula to the wholw column, can any one help ?

Zarab try in like D:D or E:E or F:F in dv formula

Hemesh, the data validation is only a criteria where there is no place for D:D or inserting other than the criteria

The formula is text lenghth less than or equal 26

Depending upon your formula you can go to data validation, Custom formula for data validation and you can select any column just by taking your mouse pointer on that column and with a simple click. i.e. if you want to select column c go to DV custom formula and type = and select column heading C with your mouse.

As FOTIS suggested your fomula must comply the DV. Please update what formula you are trying to use

Let me explain what i did again, I have a column of names I wanted to exclude all names above 26 letters, I used data validtion by selecting data validation, text lenght, less than or equal 26, then highlighted the invalid cells. I need to apply this data validation to the whole column it only applies to the first 255 cells any help/

Zarab have a look at the file data validation has been applied to whole column A1 to A1048576 with text length as min 1 and max 5

So how did you apply it to the whole column, only by selecting the cell

select the column tab from the top