Set, thank you for your help. I'll like to explain my self better. If having these records:
table_id date_time customer_id other_fields -------- ---------------- ----------- ------------ 001 08/30/2017 08:00 0015 whatever 002 08/30/2017 08:10 0025 whatever 003 08/30/2017 08:20 0025 whatever 004 08/30/2017 08:30 0011 whatever 005 08/30/2017 08:40 0014 whatever 006 08/30/2017 08:50 0025 whatever 007 08/30/2017 09:00 0021 whatever 008 08/30/2017 09:10 0024 whatever 009 08/30/2017 09:20 0017 whatever 010 08/30/2017 09:30 0025 whatever 011 08/30/2017 09:40 0026 whatever 012 08/30/2017 09:50 0026 whatever 013 08/30/2017 10:00 0018 whatever 014 08/30/2017 10:10 0015 whatever 015 08/30/2017 10:20 0013 whatever 016 08/30/2017 10:30 0025 whatever 017 08/30/2017 10:40 0011 whatever 018 08/30/2017 10:50 0011 whatever 019 08/30/2017 11:00 0032 whatever What I need is to select only the first record (based on date_time) from each customer_id. Like this: table_id date_time customer_id other_fields -------- ---------------- ----------- ------------ 001 08/30/2017 08:00 0015 whatever 002 08/30/2017 08:10 0025 whatever 004 08/30/2017 08:30 0011 whatever 005 08/30/2017 08:40 0014 whatever 007 08/30/2017 09:00 0021 whatever 008 08/30/2017 09:10 0024 whatever 009 08/30/2017 09:20 0017 whatever 011 08/30/2017 09:40 0026 whatever 013 08/30/2017 10:00 0018 whatever 015 08/30/2017 10:20 0013 whatever 019 08/30/2017 11:00 0032 whatever Regards, Hernando.
