https://communities.sas.com/t5/SAS-Programming/Proc-sql-join/m-p/282621#M57464 Depends on what you want.<BR />Try both and compare the results and see what fits your needs. Thu, 07 Jul 2016 06:38:51 GMT LinusH 2016-07-07T06:38:51Z https://communities.sas.com/t5/SAS-Programming/Proc-sql-join/m-p/282619#M57462 hi, what should be the code ? In the SMB Usage data create a another column to identify churners by using Product_id as key variable (check if the key variable is Unique ID in this case).The list of churners is given in the 'churners and labels' along with churn month. use Left join or right Join ? Thu, 07 Jul 2016 06:36:20 GMT https://communities.sas.com/t5/SAS-Programming/Proc-sql-join/m-p/282619#M57462 Prateek1 2016-07-07T06:36:20Z https://communities.sas.com/t5/SAS-Programming/Proc-sql-join/m-p/282621#M57464 Depends on what you want.<BR />Try both and compare the results and see what fits your needs. Thu, 07 Jul 2016 06:38:51 GMT https://communities.sas.com/t5/SAS-Programming/Proc-sql-join/m-p/282621#M57464 LinusH 2016-07-07T06:38:51Z