Good catch Mr.Hai.kuo. Not sure how I overlooked at it. Please ignore my previous code. This should work fine now. Code: PROC SQL; CREATE TABLE HAVE1 AS SELECT ID, invitedate AS MONTH FORMAT MMYYS., COUNT(ID) AS INVITEES FROM have QUIT; PROC FREQ DATA = HAVE1; TABLES ID * MONTH /LIST MISSING NOROW NOCOL NOPERCENT NOCUM; RUN; Output: The FREQ Procedure id MONTH Frequency ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ 1 01/2010 2 1 05/2010 1 2 01/2010 1 2 05/2010 1 2 06/2010 1 2 07/2010 1 LOG: 628 PROC SQL; 629 CREATE TABLE HAVE1 AS 630 SELECT ID, invitedate AS MONTH FORMAT MMYYS., COUNT(ID) AS INVITEES 631 FROM have 632 QUIT; NOTE: The query requires remerging summary statistics back with the original data. NOTE: Table WORK.HAVE1 created, with 7 rows and 3 columns. 633 NOTE: PROCEDURE SQL used (Total process time): real time 0.01 seconds cpu time 0.01 seconds 634 PROC FREQ DATA = HAVE1; 635 TABLES ID * MONTH /LIST MISSING NOROW NOCOL NOPERCENT NOCUM; 636 RUN; NOTE: There were 7 observations read from the data set WORK.HAVE1. NOTE: PROCEDURE FREQ used (Total process time): real time 0.03 seconds cpu time 0.01 seconds
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