golang part of plugin incorrect handle empty (rows=0) results from Clickhouse

[Slach]

need to research howto return "NODATA" instead of "ERROR" when we got empty result from ClickHouse

[Slach]

@bmanth60 JFYI

[bmanth60]

@Slach I read the PR, but I don't quite understand the fix, is it that there is a nullable and low cardinality type?

[Slach]

the main goal of fix
for most corner cases shall return multiple data frames instead of just one data.Frame

each data.Frame for each exists time series with two fields (time, value)
String fields and complex type fields used as labels

Array(Tuple( which return after apply $macro converts to multiple data.Frames use first field as label, second field as value

also, SQL queries can return nullable values and DateTime64, so I add support for this corner cases

LowCardinality also supported for properly parsing label values

Also, if we return SQL result without a timestamp field
We just return one data.Frame which contains all fields

[bmanth60]

Interesting, thanks!