@Geo- wrote:
maybe I am not clear enough,I test your code and get a wrong answer..still thank you for your help and advice..
@Geo-
Your initial requirement was: "I want to make a variable flag,if the max(date) of three tables— A,B,C are same then let flag=1 else let flag=0"
The code I've posted using the sample data I've posted does exactly that. If the sample data is not representative for your real case then you should post sample data (data steps creating such data), describe the logic you need and then show us the desired result.