mysql - SQL Query / find percentile based on rank -
i have created following tables ranks data set: position index indexl indexh amount rank 1 2.5 2 3 2000 1 1 2.5 2 3 3000 2 1 2.5 2 3 4000 3 1 2.5 2 3 5000 4 1 2.5 2 3 6000 5 2 1.5 1 2 2500 1 2 1.5 1 2 4500 2 2 1.5 1 2 6700 3 2 1.5 1 2 8900 4 2 1.5 1 2 9900 5 now want find percentile based on ranks created using indices such following output : position amount 1 3000+(4000-3000)*(2.5-2) 2 2500+(4500-2500)*(1.5-1) can me this. kinda new sql world. thanks, monica i think can want percentile_cont() aggregation function. looks want median: select position, percentile_cont(0.5) within group (order amount) median t group position; you can read more here .