判断一个variant型的是否为空值 用null
if (CDS2.aggregates[0].Value <> null) then
begin
ShowMessage(FloatToStr(CDS2.aggregates[0].value));
end;
判断一个variant型的是否为空值 用null
if (CDS2.aggregates[0].Value <> null) then
begin
ShowMessage(FloatToStr(CDS2.aggregates[0].value));
end;