在MySQL中有多个条件的情况

Question

CASE WHEN (D.BUYQ>0 AND D.SELLQ>0 AND D.series_expiry='2050-01-01') then
 sum(D.stt_INTRA_buy*least(D.buyq,D.SELLQ)*D.buyavg)+sum(D.stt_buy*(D.buyq-least(D.buyq,D.SELLQ))*D.buyavg) 
ELSE
sum(D.stt_buy*D.buyq*D.buyavg) 
 END) as xsttbuy

The case condition always held's False and it enters into else even after data being there in the database which satisfies the True condition.

Answer 1

I suspect you mean to be applying your test to each database row, not to each result row. If so, you need to move the case into the sum:

SUM(
    CASE WHEN (D.BUYQ>0 AND D.SELLQ>0 AND D.series_expiry='2050-01-01') THEN
        D.stt_INTRA_buy*LEAST(D.buyq,D.SELLQ)*D.buyavg)+D.stt_buy*(D.buyq-LEAST(D.buyq,D.SELLQ))*D.buyavg 
    ELSE
        D.stt_buy*D.buyq*D.buyavg
    END
) AS xsttbuy