根据硬编码条件过滤数据（MongoDB）

debugcn 发表于 Dev

侯赛因沙士

我试图updates在两个约会之间。因此，我有一些硬编码的条件。（请参见下面的示例）

更新集合：

{
  thread_id: 'Number',
  text: 'String',
  timestamp: 'Number',
}

问题是我只想对所有条件进行一次查询，但是我不知道该怎么做，我也不知道它是否可以实现。

例：

// Records in the updates collection
const updates = [
  { thread_id: 1, text: 'Hello', date: 2000 },
  { thread_id: 2, text: 'GoodBye!', date: 1999 },
  { thread_id: 2, text: 'This is a test', date: 3000 },
  { thread_id: 3, text: 'We are happy!', date: 6000 }
];

// Conditions (Hard-Coded)
const conditions = [
  {
    thread_id: 1,
    date_start: 1899,
    date_end: 2059
  }, {
    thread_id: 2,
    date_start: 1905,
    date_end: 2000
  }, {
    thread_id: 3,
    date_start: 1905,
    date_end: null // means no limitation
  }
];

// Results:
const results = [
  { thread_id: 1, text: 'Hello', timestamp: 2000 },
  { thread_id: 2, text: 'GoodBye!', timestamp: 1999 },
  { thread_id: 3, text: 'We are happy!', timestamp: 6000 },
]

// Query (Pseudoquery)
update.thread_id = condition.thread_id
condition.date_start <= update.timestamp <= condition.date_end

如您所见，由于该属性未在条件中设置，因此This is a test被排除并We are happy!存在end。

R2D2

也许您可以如下更改一些困难的条件：

mongos> const cond= [ {thread_id:1 ,$or:[ {date:{$lte:1899}} ,{date:{$gte:2059}}] },{thread_id:2 ,$or:[ {date:{$gte:2000}} ,{date:{$lte:1905} } ] } , {thread_id:3 , $or:[ {date:{$lte:1905}}, {date:{$gte:9999}}]}  ]
mongos> db.updates.find({$or:cond})
{ "_id" : ObjectId("5ff9b208da146da4e1359dcf"), "thread_id" : 2, "text" : "This is a test", "date" : 3000 }
mongos> db.updates.find()
{ "_id" : ObjectId("5ff9b208da146da4e1359dcf"), "thread_id" : 2, "text" : "This is a test", "date" : 3000 }
{ "_id" : ObjectId("5ff9b399da146da4e1359dd1"), "thread_id" : 1, "text" : "Hello", "date" : 2000 }
{ "_id" : ObjectId("5ff9b3aada146da4e1359dd2"), "thread_id" : 2, "text" : "GoodBye!", "date" : 1999 }
{ "_id" : ObjectId("5ff9b3c6da146da4e1359dd3"), "thread_id" : 3, "text" : "We are happy!", "date" : 6000 }
mongos> db.updates.find({$or:cond})
{ "_id" : ObjectId("5ff9b208da146da4e1359dcf"), "thread_id" : 2, "text" : "This is a test", "date" : 3000 }
mongos> db.updates.deleteMany({$or:cond})
{ "acknowledged" : true, "deletedCount" : 1 }
mongos> db.updates.find()
{ "_id" : ObjectId("5ff9b399da146da4e1359dd1"), "thread_id" : 1, "text" : "Hello", "date" : 2000 }
{ "_id" : ObjectId("5ff9b3aada146da4e1359dd2"), "thread_id" : 2, "text" : "GoodBye!", "date" : 1999 }
{ "_id" : ObjectId("5ff9b3c6da146da4e1359dd3"), "thread_id" : 3, "text" : "We are happy!", "date" : 6000 }
mongos>

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