Ruler Engine Question

Dear Sirs,
I am new , in using EMQX Enterprise Ruler engine.
I have payload as the following:
{
“/WSW/Data/batchKlt/batchID”: [
{
“v”: 21019,
“q”: 192,
“ts”: 1719304733945
},
{
“v”: 21019,
“q”: 192,
“ts”: 1719304734457
}
],
“/WSW/Data/batchKlt/kltType”: [
{
“v”: 1,
“q”: 192,
“ts”: 1719304733945
},
{
“v”: 1,
“q”: 192,
“ts”: 1719304734457
}
]
}

My Rule is the following:
SELECT
payload.“/WSW/Data/batchKlt/timestamp” as timestamp,
payload.“/WSW/Data/batchKlt/batchID” as batchID,
payload.“/WSW/Data/batchKlt/kltType” as kltType,
payload.“/WSW/Data/batchKlt/pieceCount” as pieceCount,
payload.“/WSW/Data/batchKlt/kltAmount” as kltAmount,
payload.“/WSW/Data/batchKlt/lastKlt” as lastKlt
FROM
“WA/WAB/Storage/WSW”

When process it, (in test), I have got:

batchID
0
q 192
ts 1719304733945
v 21019
1
q 192
ts 1719304734457
v 21019
kltAmount undefined
kltType
0
q 192
ts 1719304733945
v 1
1
q 192
ts 1719304734457
v 1

I need to get the value of timestamp, batchID, kltType, pieceCount, kltAmount and lastKlt.
I can not figure out:

  1. Why do I get more than one value for each item (“/WSW/Data/batchKlt/timestamp”)?
  2. What suppose to be the rule in order to extract the values for timestamp, batchID, kltType, pieceCount, kltAmount and lastKlt?

Thank you very much for the support!
Svetozar Yolov