Question

有没有办法将shell查询语法中表达的查询提交给mongo c＃driver

例如

之类的东西

Coll.find { "myrecs","$query : { x : 3, y : "abc" }, $orderby : { x : 1 } } ");

从shell指南中获取示例

Answer 1

您没有完全相同的功能。

但您可以从json创建BsonDocument以进行查询：

var jsonQuery = "{ x : 3, y : 'abc' }";
BsonDocument doc = MongoDB.Bson.Serialization
                   .BsonSerializer.Deserialize<BsonDocument>(jsonQuery);

之后，您可以从BsonDocument创建查询：

var query = new QueryComplete(doc); // or probably Query.Wrap(doc);

您可以对排序表达式执行相同的操作：

var jsonOrder = "{ x : 1 }";
BsonDocument orderDoc = BsonSerializer.Deserialize<BsonDocument>(jsonQuery);

var sortExpr = new SortByWrapper(orderDoc);

你也可以像这样为MongoCollection创建扩展方法：

public static List<T> GetItems<T>(this MongoCollection collection, string queryString, string orderString) where T : class 
{
    var queryDoc = BsonSerializer.Deserialize<BsonDocument>(queryString);
    var orderDoc = BsonSerializer.Deserialize<BsonDocument>(orderString);

    //as of version 1.8 you should use MongoDB.Driver.QueryDocument instead (thanks to @Erik Hunter)
    var query = new QueryComplete(queryDoc);
    var order = new SortByWrapper(orderDoc);

    var cursor = collection.FindAs<T>(query);
    cursor.SetSortOrder(order);

    return cursor.ToList();
}

我没有测试上面的代码。如果需要，会在以后再做。

<强>更新

刚刚测试了上面的代码，它正在运行！

你可以像这样使用它：

var server = MongoServer.Create("mongodb://localhost:27020");
var collection= server.GetDatabase("examples").GetCollection("SO");

var items = collection.GetItems<DocType>("{ x : 3, y : 'abc' }", "{ x : 1 }");

Answer 2

QueryComplete类似乎已被弃用。请改用MongoDB.Driver.QueryDocument。如下：

BsonDocument document = MongoDB.Bson.Serialization.BsonSerializer.Deserialize<BsonDocument>("{ name : value }");
QueryDocument queryDoc = new QueryDocument(document);
MongoCursor toReturn = collection.Find(queryDoc);

Answer 3

这是我编写的一个Web服务函数，您可以通过筛选器查询，限制和跳过分页以及您想要的任何集合的排序查询！它通用且快速。

    /// <summary>
    /// This method returns data from a collection specified by data type
    /// </summary>
    /// <param name="dataType"></param>
    /// <param name="filter">filter is a json specified filter. one or more separated by commas.  example: { "value":"23" }  example: { "enabled":true, "startdate":"2015-10-10"}</param>
    /// <param name="limit">limit and skip are for pagination, limit is the number of results per page</param>
    /// <param name="skip">skip is is the page size * page. so limit of 100 should use skip 0,100,200,300,400, etc. which represent page 1,2,3,4,5, etc</param>
    /// <param name="sort">specify which fields to sort and direction example:  { "value":1 }  for ascending, {"value:-1} for descending</param>
    /// <returns></returns>
    [WebMethod]
    public string GetData(string dataType, string filter, int limit, int skip, string sort) {
        //example: limit of 100 and skip of 0 returns the first 100 records

        //get bsondocument from a collection dynamically identified by datatype
        try {
            MongoCollection<BsonDocument> col = MongoDb.GetConnection("qis").GetCollection<BsonDocument>(dataType);
            if (col == null) {
                return "Error: Collection Not Found";
            }

            MongoCursor cursor = null;
            SortByWrapper sortExpr = null;

            //calc sort order
            try {
                BsonDocument orderDoc = BsonSerializer.Deserialize<BsonDocument>(sort);
                sortExpr = new SortByWrapper(orderDoc);
            } catch { }

            //create a query from the filter if one is specified
            try {
                if (filter != "") {
                    //sample filter: "{tags:'dog'},{enabled:true}"
                    BsonDocument query = BsonSerializer.Deserialize<BsonDocument>(filter);
                    QueryDocument queryDoc = new QueryDocument(query);
                    cursor = col.Find(queryDoc).SetSkip(skip).SetLimit(limit);

                    if (sortExpr != null) {
                        cursor.SetSortOrder(sortExpr);
                    }

                    return cursor.ToJson();
                }
            } catch{}


            //if no filter specified or the filter failed just return all
            cursor = col.FindAll().SetSkip(skip).SetLimit(limit);

            if (sortExpr != null) {
                cursor.SetSortOrder(sortExpr);
            }

            return cursor.ToJson();
        } catch(Exception ex) {
            return "Exception: " + ex.Message;
        }
    }

假设我的集合中有这些记录名为“mytest2”：

[{ "_id" : ObjectId("54ff7b1e5cc61604f0bc3016"), "timestamp" : "2015-01-10 10:10:10", "value" : "23" }, 
 { "_id" : ObjectId("54ff7b415cc61604f0bc3017"), "timestamp" : "2015-01-10 10:10:11", "value" : "24" }, 
 { "_id" : ObjectId("54ff7b485cc61604f0bc3018"), "timestamp" : "2015-01-10 10:10:12", "value" : "25" }, 
 { "_id" : ObjectId("54ff7b4f5cc61604f0bc3019"), "timestamp" : "2015-01-10 10:10:13", "value" : "26" }]

我可以使用以下参数进行Web服务调用，返回从第一页开始的100条记录，其中值＆gt; = 23，值＆lt; = 26，按降序排列

dataType: mytest2
filter: { value: {$gte: 23}, value: {$lte: 26} }
limit: 100
skip: 0
sort: { "value": -1 }

享受！

Answer 4

以下是我用于从字符串和.NET对象转换为BSON查询的一些例程（这是业务对象包装器的一部分，因此有几个引用该类）：

    public QueryDocument GetQueryFromString(string jsonQuery)
    {
        return new QueryDocument(BsonSerializer.Deserialize<BsonDocument>(jsonQuery));
    }

    public IEnumerable<T> QueryFromString<T>(string jsonQuery, string collectionName = null)
    {
        if (string.IsNullOrEmpty(collectionName))
            collectionName = this.CollectionName;

        var query = GetQueryFromString(jsonQuery);            
        var items = Database.GetCollection<T>(collectionName).Find(query);

        return items as IEnumerable<T>;
    }


    public IEnumerable<T> QueryFromObject<T>(object queryObject, string collectionName = null)
    {
        if (string.IsNullOrEmpty(collectionName))
            collectionName = this.CollectionName;

        var query = new QueryDocument(queryObject.ToBsonDocument());
        var items = Database.GetCollection<T>(collectionName).Find(query);

        return items as IEnumerable<T>;
    }

使用它们很容易通过字符串或对象参数查询：

var questionBus = new busQuestion();           
var json = "{ QuestionText: /elimination/, GroupName: \"Elimination\" }";
var questions = questionBus.QueryFromString<Question>(json);

foreach(var question in questions) { ... }

或使用对象语法：

var questionBus = new busQuestion();            
var query = new {QuestionText = new BsonRegularExpression("/elimination/"), 
                 GroupName = "Elimination"};
var questions = questionBus.QueryFromObject<Question>(query);

foreach(var question in questions) { ... }

我喜欢对象语法，因为在C＃代码中写出比在JSON字符串中处理嵌入式引号更容易，如果它们是手动编码的。

Answer 5

使用official C# driver，您可以执行以下操作：

var server = MongoServer.Create("mongodb://localhost:27017");
var db = server.GetDatabase("mydb");
var col = db.GetCollection("col");

var query = Query.And(Query.EQ("x", 3), Query.EQ("y", "abc"));
var resultsCursor = col.Find(query).SetSortOrder("x");
var results = resultsCursor.ToList();

来自shell的等效查询将是：

col.find({ x: 3, y: "abc" }).sort({ x: 1 })

我可以使用mongodb c＃驱动程序进行文本查询

5 个答案: