How to check if I have duplicates without perfectly duplicated obs

[Hatim Tareq]

Dear All,

I am a long data, with duplicated IDs, as there are obs for different dates. I would like to check if there are difference between the variables for each ID and Date (as my title say: duplicates without perfectly duplicated obs)

  
 input id date char1 char2 char3 char4
1 1/1/2009 4 5 4 0  
1 2/22009 4 5 5 10
1 3/3/2009 4 5 4 10
1 4/4/2009 4 5 4 10
 1 5/5/2009 4 5 4 10  
end

I have tried to use duplicates, but I have more than 40 variables, so it is practical to use

I have also tried to use collapse (checked the help in stata) but don't know if its the correct way to go.

ds date, not
collapse (lastnm) `r(varlist)', by(date)

Thank you for your help in advance.

[Hatim Tareq]

Any help please.

[Nick Cox]

duplicates list char1-char4

would with your example indicate that there are duplicates on those variables. And so on.

[Hatim Tareq]

Thank you Nick.

I think it works, I will investigate the output and let you know.

Thank you for you help.