Insert IoT message array as multiple rows in DynamoDB - amazon-web-services

Question

I'm starting a new project that involves some IoT devices sending every 5 minutes their status and other info to AWS IoT.
The structure of the message is the following:
{
"SNC":"C_SN_15263217541",
"STATUS":"enable",
"PLANT":{
"PNAME":"nomeimpianto",
"DVS":{
"SD":[{
"SDSN":"LD_SN_15263987543",
"TT":"30/11/17 4:37 PM",
"STATUS":"Enable",
"TON":"3sec",
"TOFF":"6min",
"QTAC":"125",
"ALCODE":"201",
"ALDESC":"assenza scarico"
},
{
"SDSN":"LD_SN_15263987543",
"TT":"30/11/17 4:39 PM",
"STATUS":"Enable",
"TON":"3sec",
"TOFF":"6min",
"QTAC":"125",
"ALCODE":"201",
"ALDESC":"assenza scarico"
},
{
"SDSN":"LD_SN_15263997545",
"TT":"30/11/17 4:37 PM",
"STATUS":"Enable",
"TON":"3sec",
"TOFF":"6min",
"QTAC":"125"
},
{
"SDSN":"LD_SN_15263997545",
"TT":"30/11/17 4:39 PM",
"STATUS":"Enable",
"TON":"3sec",
"TOFF":"6min",
"QTAC":"125"
},
{
"SDSN":"LD_SN_15123987543",
"TT":"30/11/17 4:37 PM",
"STATUS":"Enable",
"TON":"3sec",
"TOFF":"6min",
"QTAC":"125"
},
{
"SDSN":"LD_SN_15123987543",
"TT":"30/11/17 4:39 PM",
"STATUS":"Enable",
"TON":"3sec",
"TOFF":"6min",
"QTAC":"125"
}
]
}
}
}
I created a rule that inserts the message on DynamoDB, and it's working nicely, but I'd need to create, for each message received, one row for each item in PLANT.DVS.SD.
My DynamoDB table has as hashkey the field PLANT.DVS.SD[x].SDSN and as sort field PLANT.DVS.SD[x].TT.
I tried with a DynamoDBv2 rule and I managed only to create one row per message with the whole array, but it's not what I'm looking for.
So basically the problem is that I don't know how to structure the SQL statement in the rule definition.
I know that PLANT.DVS.SD's max length is 12, so the only idea that I've got is to create 12 IoT rules that insert on DynamoDB only the element at a specific position. Although if there is a better way to solve this problem dynamically, it'd be appreciated!