How to get count of total records in a table

[deleted_user]

Is there a simple way to get a count of the total number of records in a table, perhaps when using Proc SQL?

Thanks in advance....looking forward to your replies!

[MohamedS · Accepted solution]

Hi,

You can use the function:

select count(*) as countrec from tablename;

within your proc sql.

If the table is a SAS dataset, it has its size in the header and is accessible with the NOBS= option:

%macro get_table_size(inset,macvar);
 data _null_;
  set &inset NOBS=size;
  call symput("&macvar",size);
 stop;
 run;
%mend;

This method takes O(k) time (that is constant time) and doesn't require scanning through the table, O(n), to count the records.  Use it like this:

%let reccount=;
%get_table_size(sashelp.cars,reccount);
%put &=reccount;

[deleted_user]

Mohamed,

Thanks for your reply! That worked for what I wanted to know about my dataset.

[deleted_user]

If the table is a SAS dataset, it has its size in the header and is accessible with the NOBS= option:

%macro get_table_size(inset,macvar);

data _null_;
set &inset NOBS=size;
call symput("&macvar",size);
stop;
run;
quit;

%mend;

This method takes O(k) time (that is constant time) and doesn't require scanning through the table, O(n), to count the records.

To make the macro more robust, you would want to add a conditional wrapper:

%if %sysfunc(exist(&inset)) %then %do;


and then have some appropriate %else %do; for when the &inset doesn't "exist".

I'm not sure if there is a generic way to distinguish a permanent SAS dataset from a database table. I don't know if NOBS= will work for a database (Oracle, DB2, Sybase, Access, SQL Server, MySQL, etc. ). Message was edited by: Chuck

[deleted_user]

Chuck,

Interesting.... and thank you for the information. I'll put that to good use as time progresses.

[deleted_user]

in proc sql, you could also go against a table's metadata in dictionary.tables to get the nobs in a data set:
proc sql;
select nobs
from dictionary.tables
where libname eq 'SASHELP'
and memname eq 'ZIPCODE';
quit;

this approach avoids actually reading the data set. if you're looking at a very large table, this can save lots of time; if you're accessing a remote library, it should also save time. this only appears to work for sas data sets and not for databases (sql, mysql, oracle, etc).

i've also been unsuccessful with my attempts to access the view sashelp.vtable:
data _null_;
set sashelp.vtable;
where libname eq 'SASHELP'
and memname eq 'ZIPCODE';
put nobs;
run;

[deleted_user]

And thank you also, Richard. So many ways to do the same thing!

[deleted_user]

I have no knowledge of macros, so I would like to know how to use the get_table_size macro.

If I have a data step:

data new_table;
set old_table;



run;

is it possible to call the macro in the same data step and assign the new_table number of rows to a variable nRows.

I would like to see the macro call:

nRows=%get_table_size( ?, ? ); /* Something like that? */

[deleted_user]

Chuck,
on a more basic level, what does the "&macvar" stand for? is this the name of the new variable you are creating which contains the total # of records?

thanks,
abc

[Peter_C]

for sas information about a table in a dbms, see corresponding rows in sashelp.vmember and sashelp.vviews.
However, each dbms has its database information files equivalent to dictionary.tables. these probably could advise number of rows and columns (last time stats were collected). these resources are database dependant.

PeterC

[RichardH_sas]

Since this is an EG forum, I'll mention that in EG you can right-click on a table and see the number of rows under Properties in the General pane. If it's a DMBS table and not a SAS data set, by default this will say unknown. You can change that under Tools \ Options \ Data General then check "Always obtain the total record count for DBMS tables". There could be performance issues with this, FYI, which is why it's not checked by default.