改成对应类型的空值,比如 table(12 as A,00i as B,13 as C), 如果是SYMBOL类型的,使用''来代表空值。
回答于 2023-08-18 17:19
如果volumes所在盘是nfs盘,请以v3 版本挂载,dolphindb不支持 v4 版本挂载的nfs盘: mount -t nfs -o -o v3,local_lock=all ...
回答于 2023-08-17 17:59
使用sqlColAlias: sqlColAlias(makeCall(def(x){return x, x+1}, sqlCol("close")), ["c1","c2"])
回答于 2023-08-15 18:21
d1 = {"a1":"a","a2":"a"}tb = table(`a1`a2`a3 as `a,`b1`b2`b3 as `b)update tb set a=nullFill!(string(d1[a]), a)
回答于 2023-08-15 18:16
可以使用parseExpr解析批量输入的表达式: metrics=parseExpr("[f1(args), f2(args), f3(args)]")
回答于 2023-08-04 10:28
可以使用volumeBar函数 first(price) as openPrice ,max(price) as highPrice ,min(price) as lowPrice ,last(price) as closePrice ,sum(qty) as totalQty ,sum(qty*price) as amountfrom t1group by volumeBar(qty, 1000)
回答于 2023-08-04 10:06