Hi @ysmnkmlia and welcome to the SAS Support Communities!
Similar to Patrick's solution, you can also replace the KEEP statement with a KEEP= dataset option and then apply the CMISS function to the _ALL_ variable list:
data work.Project_pisa2022;
set pisa2022.Project_pisa2022(keep=CNT ST004D01T
PV1MATH PV2MATH PV3MATH PV4MATH PV5MATH PV6MATH PV7MATH PV8MATH PV9MATH PV10MATH
PV1READ PV2READ PV3READ PV4READ PV5READ PV6READ PV7READ PV8READ PV9READ PV10READ
PV1SCIE PV2SCIE PV3SCIE PV4SCIE PV5SCIE PV6SCIE PV7SCIE PV8SCIE PV9SCIE PV10SCIE);
where CNT in('MYS', 'SGP', 'CHE');
if cmiss(of _all_)=0;
run;
... View more
