proc sql

[manya92]

What is the difference between 

proc sql ;

     create table 1 as

    select DISTINCT enrolid, age, sex

    from have 

quit ;

VS

proc sql ;

     create table 2 as

    select  enrolid, age, sex

    from have 

quit ;

VS

proc sql ;

     create table 3 as

    select DISTINCT enrolid

    from have 

quit ;

Q1. Will i get different no. of observations for each of these datasets? If yes why ?

Q2. What is the difference between these three .

Thanks

[ballardw]

Run the code and see. Create data if needed, include some duplicate rows.

[Reeza]

You should mock up some data and test your code. Here's some mock data for you. Run it against each of the tables and see what you're results are. Note that the first table has duplicates and the second does not. 

data have1;
set sashelp.class;
enrolid = _n_;
if _n_ in (1, 5, 9) then output;
output;
keep enrolid age sex;
run;

data have2;
set sashelp.class;
enrolid = _n_;
keep enrolid age sex;
run;

---

@manya92 wrote:

What is the difference between 

proc sql ;

     create table 1 as

    select DISTINCT enrolid, age, sex

    from have 

quit ;

VS

proc sql ;

     create table 2 as

    select  enrolid, age, sex

    from have 

quit ;

VS

proc sql ;

     create table 3 as

    select DISTINCT enrolid

    from have 

quit ;

Q1. Will i get different no. of observations for each of these datasets? If yes why ?

Q2. What is the difference between these three .

Thanks

---

[manya92]

will try. thanks