过滤时遇到问题，布尔问题

Question

“open”假设采用布尔值，我应该能够用它过滤结果，但结果是一个空数组，请原谅凌乱的代码

让 queryToMatch = [{$match: {name: project}},{$unwind:"$issues"}];

  if(_id != undefined){
    queryToMatch.push({$match: {"_id": _id}})
  }
  if(open != undefined){
    queryToMatch.push({$match: {"open": open}})
  }
  if(issue_title != undefined){
    queryToMatch.push({$match:{"issue_title": issue_title}})
  }
  if(issue_text != undefined){
    queryToMatch.push({$match:{"issue_text": issue_text}})
  }
  if(created_by != undefined){
    queryToMatch.push({$match:{"created_by": created_by}})
  }
  if(assigned_to != undefined){
    queryToMatch.push({$match:{"assigned_to": assigned_to}})
  }
  if(status_text != undefined){
    queryToMatch.push({$match:{"status_text": status_text}})
  }
  console.log(queryToMatch)
  res.json("works")

  Project.aggregate(queryToMatch, (err, data) => {
    //console.log(data)
    res.json(data)
  })

Answer 1

您没有包含架构或您尝试查询的示例文档。出于这个原因，我的回答可能与您的预期不同。

如果我添加以下文件...

db.test.insert(
{
    "_id" : ObjectId("60b44ae6af90ae8f4deca589"),
    "name": "project",
    "open": "open",
    "issue_title": "mytitle",
    "issue_text": "mytext",
    "created_by": "barry",
    "assigned_to": "john",
    "status_text": "mystatus",
    "issues": [
        {
            "issue_type": "type1",
            "issue_date": new Date
        },
        {
            "issue_type": "type2",
            "issue_date": new Date
        },
        {
            "issue_type": "type3",
            "issue_date": new Date
        },
    ]
}
)

我可以运行以下 mongo shell 命令...

var _id = ObjectId("60b44ae6af90ae8f4deca589");
var open = "open";
var issue_title = "mytitle";
var issue_text = "mytext";
var created_by = "barry";
var assigned_to = "john";
var status_text = "mystatus";

let queryToMatch = [{"$match": {"name": "project"}},{$unwind:"$issues"}];

if(_id != undefined){
    queryToMatch.push({$match: {"_id": _id}})
  }
  if(open != undefined){
    queryToMatch.push({$match: {"open": open}})
  }
  if(issue_title != undefined){
    queryToMatch.push({$match:{"issue_title": issue_title}})
  }
  if(issue_text != undefined){
    queryToMatch.push({$match:{"issue_text": issue_text}})
  }
  if(created_by != undefined){
    queryToMatch.push({$match:{"created_by": created_by}})
  }
  if(assigned_to != undefined){
    queryToMatch.push({$match:{"assigned_to": assigned_to}})
  }
  if(status_text != undefined){
    queryToMatch.push({$match:{"status_text": status_text}})
  }

...那么我可以发出以下汇总语句...

db.test.aggregate(queryToMatch).pretty()

...我得到以下结果...

{
    "_id" : ObjectId("60b44ae6af90ae8f4deca589"),
    "name" : "project",
    "open" : "open",
    "issue_title" : "mytitle",
    "issue_text" : "mytext",
    "created_by" : "barry",
    "assigned_to" : "john",
    "status_text" : "mystatus",
    "issues" : {
        "issue_type" : "type1",
        "issue_date" : ISODate("2021-05-31T02:46:04.670Z")
    }
}
{
    "_id" : ObjectId("60b44ae6af90ae8f4deca589"),
    "name" : "project",
    "open" : "open",
    "issue_title" : "mytitle",
    "issue_text" : "mytext",
    "created_by" : "barry",
    "assigned_to" : "john",
    "status_text" : "mystatus",
    "issues" : {
        "issue_type" : "type2",
        "issue_date" : ISODate("2021-05-31T02:46:04.670Z")
    }
}
{
    "_id" : ObjectId("60b44ae6af90ae8f4deca589"),
    "name" : "project",
    "open" : "open",
    "issue_title" : "mytitle",
    "issue_text" : "mytext",
    "created_by" : "barry",
    "assigned_to" : "john",
    "status_text" : "mystatus",
    "issues" : {
        "issue_type" : "type3",
        "issue_date" : ISODate("2021-05-31T02:46:04.670Z")
    }
}

看来您的代码确实可以在 mongo shell 的上下文中工作。我的建议是先将 $match 阶段组合在一起，然后执行 $unwind。我假设您通过push 附加的每个谓词都旨在成为“与”条件，而不是“或”条件。这是经过所有逻辑恶作剧之后聚合的最终结果......

[
    {
        "$match" : {
            "name" : "project"
        }
    },
    {
        "$unwind" : "$issues"
    },
    {
        "$match" : {
            "_id" : ObjectId("60b44ae6af90ae8f4deca589")
        }
    },
    {
        "$match" : {
            "open" : "open"
        }
    },
    {
        "$match" : {
            "issue_title" : "mytitle"
        }
    },
    {
        "$match" : {
            "issue_text" : "mytext"
        }
    },
    {
        "$match" : {
            "created_by" : "barry"
        }
    },
    {
        "$match" : {
            "assigned_to" : "john"
        }
    },
    {
        "$match" : {
            "status_text" : "mystatus"
        }
    }
]

也许这是一个更简洁、更易于阅读的查询...

[
    {
        "$match" : {
            "_id" : ObjectId("60b44ae6af90ae8f4deca589"),
            "name" : "project",
            "open" : "open",
            "issue_title" : "mytitle",
            "issue_text" : "mytext",
            "created_by" : "barry",
            "assigned_to" : "john",
            "status_text" : "mystatus"
        }
    },
    {
        "$unwind" : "$issues"
    },
]

请考虑为 $match 谓词创建一个对象，而不是使用 push...

var match = new Object();
match.name = "project";

if(_id != undefined){
    match._id = _id;
  }
  if(open != undefined){
    match.open = open;
    
  }
  if(issue_title != undefined){
    match.issue_title = issue_title;
  }
  if(issue_text != undefined){
    match.issue_text = issue_text;
  }
  if(created_by != undefined){
    match.created_by = created_by;
  }
  if(assigned_to != undefined){
    match.assigned_to = assigned_to;
  }
  if(status_text != undefined){
    match.status_text = status_text;
  }
  
  
  
  let queryToMatch = [{"$match": match},{$unwind:"$issues"}];
  db.test.aggregate(queryToMatch).pretty()