db.test_mongo_fckp.remove({})
db.test_mongo_fckp.insertMany([
{field: [1,2,3]},
{field: []},
{field: ['']},
{field: [0]},
{field: 1},
{field_1: 1}
])
db.test_mongo_fckp.find()
db.test_mongo_fckp.createIndex({'field': 1})
db.test_mongo_fckp.find({'field': {'$gt': []}})
db.test_mongo_fckp.dropIndex({'field': 1})
db.test_mongo_fckp.find({'field': {'$gt': []}})