DolphinDB技术分析模块select子句查询出错

Question

图为表架构：

查询数据时该行报错：

select *,bBands(close, 5, 2, 2, 0) as `high`mid`low  from kline

错误信息是：

The calculated column was not initialized or an exception was raised.

但是，我试过的另一个脚本没有报错：

close = 7.2 6.97 7.08 6.74 6.49 5.9 6.26 5.9 5.35 5.63 3.81 3.935 4.04 3.74 3.7 3.33 3.64 3.31 2.69 2.72
date = (2020.03.02 + 0..4 join 7..11).take(20)
symbol = take(`F,10) join take(`GPRO,10)
t = table(symbol, date, close) 
select *, bBands(close, 5, 2, 2, 2) as `high`mid`low from t context by symbol

为什么会出现错误以及如何在我的代码中避免它？

Answer 1

出现此错误是因为列的名称与布林带的 UP 和 DN 一致。

您可以使用以下代码：

select *,bBands(close, 5, 2, 2, 0) as `bBand_high`mid`bBand_low  from kline.