Raj,

I'd expand on Bob's response and make a couple of minor corrections.

First, the concepts aren't limited to proc summary, but are general to many SAS procs. In fact, the documentation provides a lot more detail in its section on proc summary's relative .. proc means (see, e.g.: http://support.sas.com/documentation/cdl/en/proc/61895/HTML/default/viewer.htm#/documentation/cdl/en/proc/61895/HTML/default/a000146728.htm

or, in short form: http://xrl.us/bhuwpz )

In some procs, 'table' or 'model' might be the keyword used rather than 'var'.

The 'by' statement gives you a way to mix orders so that all don't have to be ascending or descending, lets you use the #byval variable and, I believe, requires less resources (thus can handle more complex designs before confronting memory problems).

The ID statement gives you a way to include additional, non-summarized values. The documentation provides more detail than I could provide here but, rather than the first value encountered in a by or class group combination, it can either be the minimum or maximum value within a by or class group combination.

HTH, Art --------------- On Aug 1, 8:12 am, Bob <techsavvy...@yahoo.com> wrote: > Here is a good article from SAS on the PROC SUMMARY. That is the > procedure where those are primarily used. > > http://support.sas.com/documentation/cdl/en/proc/61895/HTML/default/v... > > CLASS and BY are used to tell SAS what variable(s) to use when > summarizing the dataset. (The difference being BY variables must be > presorted). ID is used to tell SAS, 'don't summarize by this variable, > but display the first value for a given BY variable combination'. VAR > is used for numeric variables you would like a calculation performed > on (usually summation). > > Example: > proc summary data=[input dataset] nway missing; > class [var1] [var2]; > id [var3]; > var [var4]; > output out=[output dataset] sum=; > run; > > This summarizes the input dataset by var1 and var2, displays var3, and > subtotals var4 for each var1/var2 combination. Make sense? > > On Aug 1, 3:17 am, Raj <rajiv...@gmail.com> wrote: > > > > > Hi, > > > Can somebody explain where we use VAR,ID,BY,CLASS and what is the > > difference between each one with an example. > > > Thanks for the help. > > > Regards, > > Raj- Hide quoted text - > > - Show quoted text -