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我正在使用MongoDB並具有以下格式的集合。我如何修改MongoDB查詢以適應集合結構
db.options.find({ "undersymbol" : "UBSC"}).pretty()
{
"finalsymbol" : "UBSC",
"option_exp" : [
{
"expiration_dt" : "2015-01-17",
"days_to_expire" : 638,
"low_strike" : 120,
"high_strike" : 190,
"no_of_strikes" : 86,
"options" : [
{
"strikeprice" : "120.0",
"chain_type" : "call",
"symbol" : "UBSC"
}
]
},
"expiration_dt" : "2015-01-18",
"days_to_expire" : 656,
"low_strike" : 34,
"high_strike" : 455,
"no_of_strikes" : 67,
"options" : [
{
"strikeprice" : "420.0",
"chain_type" : "call",
"symbol" : "UBSC"
}
]
}
}
]
}
現在我使用的folllowing查詢從我的收藏中提取數據
BasicDBObject query = new BasicDBObject();
query.put("finalsymbol", "UBSC");
OptionsData ocd = (OptionsData) coll.findOne(query);
正在形成的查詢是
{ "finalsymbol" : "UBSC"}
是否有可能,可我在查詢中還包括expiration_dt
還有finalsymbol
,這樣性能會提高?