topic Re: Why where clause did not work? in SAS Programming

Why where clause did not work?

Phil_NZ — Tue, 16 Mar 2021 09:46:35 GMT

Hi all SAS Users,

Today I faced a problem that where clause did not work in my datastep

My code is

data filter;
	set var_cal;
	where n(ajexdi,prccd_abs_,trfd)=3 or n(prccd_abs_,prchd,prcld)=3
		and
		prccd_abs_ > 0
		and
		tpci='0'
		and
		prcstd=3 or (prcstd=4 and LOC='CAN') or prcstd=10
		and
		input(SIC, 4.) not in (4900:4949, 6000:6999)
		and
		raw_return<2
	;
run;

I have a look on the dataset and see that in the dataset filter, return >2 still exists, could you please let me know what is wrong with my code? This is the proc means for variable "raw_return" in two files.

Warmest regards.

Re: Why where clause did not work?

Kurt_Bremser — Tue, 16 Mar 2021 09:51:40 GMT

Because of the precedence of AND before OR, your condition is equivalent to:

where
  n(ajexdi,prccd_abs_,trfd)=3
  or (
    n(prccd_abs_,prchd,prcld)=3
    and
    prccd_abs_ > 0
    and
    tpci='0'
    and
    prcstd=3
  )
  or (
    prcstd=4
    and
    LOC='CAN'
  )
  or (
    prcstd=10
    and
    input(SIC, 4.) not in (4900:4949, 6000:6999)
    and
    raw_return<2
  )
;

Check if this is what you intended.

Re: Why where clause did not work?

yabwon — Tue, 16 Mar 2021 09:53:35 GMT

How the brackets should be set in the where clause?? You have bot OR and AND operator there so the condition my be evaluated different that you expect it to be.

Look into the log and see how SAS resolved the condition from the where clause and if it is what you expect it to be.

For example:

data filter;
	set var_cal;
	where n(ajexdi,prccd_abs_,trfd)=3 or n(prccd_abs_,prchd,prcld)=3
		and
		prccd_abs_ > 0
		and
		tpci='0'
		and
		( prcstd=3 or (prcstd=4 and LOC='CAN') or prcstd=10 ) /* brackets setup 1*/
		and
		input(SIC, 4.) not in (4900:4949, 6000:6999)
		and
		raw_return<2
	;
run;

data filter;
	set var_cal;
	where ( n(ajexdi,prccd_abs_,trfd)=3 or n(prccd_abs_,prchd,prcld)=3
		and
		prccd_abs_ > 0
		and
		tpci='0'
		and
		prcstd=3)  or  ( (prcstd=4 and LOC='CAN') ) or ( prcstd=10 /* brackets setup 2*/
		and
		input(SIC, 4.) not in (4900:4949, 6000:6999)
		and
		raw_return<2)
	;
run;

All the best

Bart

Re: Why where clause did not work?

Phil_NZ — Tue, 16 Mar 2021 13:54:37 GMT

Hi @KurtBremser and @yabwon

Thank you for your explanation, it is my fault that I forget to set the brackets reasonably. My new code is as below, it means that the new code need to satisfy all rows from "where" clause.

data filter; set var_cal; where (n(ajexdi,prccd_abs_,trfd)=3 or n(prccd_abs_,prchd,prcld)=3) and prccd_abs_ > 0 and tpci='0' and (prcstd=3 or (prcstd=4 and LOC='CAN') or prcstd=10) and (input(SIC, 4.) not in (4900:4949, 6000:6999)) and raw_return<2 ; run;

However, the log is quite strange to me regarding the code

(input(SIC, 4.) not in (4900:4949, 6000:6999))

The log is

NOTE: There were 8368199 observations read from the data set WORK.VAR_CAL.
      WHERE ((N(ajexdi, prccd_abs_, trfd)=3) or (N(prccd_abs_, prchd, prcld)=3)) and (prccd_abs_>0) and (tpci='0') and (prcstd in 
      (3, 10) or ((prcstd=4) and (LOC='CAN'))) and (raw_return<200) and ((INPUT(SIC, 4.) not = INT(INPUT(SIC, 4.))) or  not 
      ((INPUT(SIC, 4.)>=4900 and INPUT(SIC, 4.)<=4949) or (INPUT(SIC, 4.)>=6000 and INPUT(SIC, 4.)<=6999)));

What I want to achieve for such line of code is to exclude all firms having SIC (4-digit number under character type) in (4900:4949, 6000:6999)

I do not know why the log shows this one (I did not set this condition in my filter)

(INPUT(SIC, 4.) not = INT(INPUT(SIC, 4.))) or

Can you please help me to sort it out?

Warm regards.

Re: Why where clause did not work?

yabwon — Tue, 16 Mar 2021 14:43:49 GMT

This:

(INPUT(SIC, 4.) not = INT(INPUT(SIC, 4.)))

is to exclude non-integers from possible list of values.