MSSQL查询到节点红线图

Question

我试图从MSSQL中查询数据并将其显示为Node Red中的折线图。

我的SQL数据看起来像

1556029184000   0.0675168918918922

1556029139000   0.0675515463917528

1556029079000   0.0679347826086958

1556029019000   0.0674082568807342

1556028959000   0.0674431818181822

1556028898000   0.0675537634408605

1556028838000   0.0673611111111115

1556028779000   0.0675917431192663

1556028719000   0.06744212962963

1556028659000   0.0673148148148151

左列是转换为Epoch的时间戳，右列是要绘制的值。

节点红色调试显示：

[{"x":"1556029788000","y":0.06772222222222232}, 
 {"x":"1556029738000","y":0.06855053191489367}, 
 {"x":"1556029678000","y":0.06858333333333343}, 
 {"x":"1556029619000","y":0.06751146788990835}, 
 {"x":"1556029559000","y":0.06805180180180205}, 
 {"x":"1556029499000","y":2.714885321100926}, 
 {"x":"1556029439000","y":11.43350290697674}, 
 {"x":"1556029378000","y":6.6709253246753235}, 
 {"x":"1556029319000","y":0.06748842592592619}, 
 {"x":"1556029259000","y":0.06760714285714318}]

图表中没有显示任何内容。我对所有这些（除了SQL之外）都是新手，所以任何和所有帮助都表示赞赏。

谢谢大家

Answer 1

node-red-dashboard侧边栏帮助有一个链接到details格式，用于将数据传递到图表节点。

你现在拥有的是一个msg.payload，它包含一系列具有x和y值的对象。这些需要移动到msg.payload.data字段，如下所述：

[{
"series": ["A", "B", "C"],
"data": [
    [{ "x": 1504029632890, "y": 5 },
     { "x": 1504029636001, "y": 4 },
     { "x": 1504029638656, "y": 2 }
    ],
    [{ "x": 1504029633514, "y": 6 },
     { "x": 1504029636622, "y": 7 },
     { "x": 1504029639539, "y": 6 }
    ],
    [{ "x": 1504029634400, "y": 7 },
     { "x": 1504029637959, "y": 7 },
     { "x": 1504029640317, "y": 7 }
    ]
],
"labels": [""]
}]