想取每只券在时序上的累计收益率
类似这样:
ptf_stock_indic_sum = select
swcode,
sum(return_ctbt * adj_value) as return_ctbt_sum,
cumprod(1+return_ratio)-1 as cum_return_ratio,
sum(weight)\tradeDayCount as avg_weight
from lj(ptf_positions_stock, pf_adj_value, `trade_dt)
group by swcode;
但是这样会报错。