Excel 2010, generate 6 digit unique random number for ID column A

[fernandg]

How do I create a 6 digit unique random number for use as an ID in column A. Once created the rows with preexisting 6 digit unique random ID numbers must not change every time new rows are added.

Thank you,
Gary

 

[shg]

Select the range of cells, paste the formula in the formula bar, press and hold the Ctrl and Shift keys, then press Enter.

If you do that, curly braces will appear around the formula.

 

[fernandg]

Seems like the easiest solution is to create a column of =RANDBETWEEN(100000,999999) and then use the Copy and Paste Value commands o build a new column. Then run the Remove Duplicates command. This creates a quick set of 6 digit unique random numbers not in sequence. These type numbers are good for security door codes and such. Thanks you for all your help!