Hi all and sorry for my poor english
I have a document like
{
"uuid": "SkDHvXr9ES",
"userRole": "9qvfWg3isp",
"devices":[
{"uuid": "hwb258pc7x", "macAddress":["9DGSsuAX4M", "ChypSa8tWx", "fIWrArQyDA", "PQjcvOkHYh",…},
{"uuid": "NpfJtvNYiQ", "macAddress":["Jj3zHklLQF", "pYbovxzI29", "Ic8wgRa_eE", "eLYktPz2Js",…},
{"uuid": "kGLJzGdgft", "macAddress":["XT7BUrUm5q", "OQNpRg7oRk", "9khaKN_3OV", "7wrWWlG51z",…},
{"uuid": "_yUh1Icaex", "macAddress":["xJ1MkTj10D", "j5YJhOQjZF", "EVVN2A4Di8", "2yysRuUTfp",…},
{"uuid": "thDqf3yKJw", "macAddress":["X233a9UN8p", "uGwxy38nWW", "3zAPY_P5QK", "z7pDSzf1Dl",…}
]
}
and I like to count length of devices array for all documents.