1

我希望有可能在运行时添加查询。我使用“旧”驱动程序的解决方案是这样的。 

    // A List does hold the queries
    List<IMongoQuery> QueryConditionList = new List<IMongoQuery>();

    void AddQuery(string sType, string sField, string sValue)
    {
        // I can add of course several Queries
        if (sType == "EQ")
            QueryConditionList.Add(Query.EQ(sField, sValue));
        else if (sType == "GT")
            QueryConditionList.Add(Query.GT(sField, sValue));
        else if (sType == "LT")
            QueryConditionList.Add(Query.LT(sField, sValue));
    }
    // At some point you can execute the queries
    void ExecuteQuery()
    {
        // Combine all to on "And" Query ("Or" would be possible as well)
        IMongoQuery query = Query.And(QueryConditionList);
        // Then I can get my cursor with a Find
        MongoCursor<BsonDocument> mc = MoCollection.Find(query);

        // Do anything with the cursor...
    }

这确实工作得很好。但是我不知道如何使用新语法来做到这一点。我所有的方法都不是动态的。喜欢：

var builder = Builders<BsonDocument>.Filter;
var filter = builder.Eq(Field1, Value1) & builder.Eq(Field2, Value2);

我想我可以添加更多过滤器，例如

filter.add(builder.Eq(Field3, Value3)); // But of course I  can't
4

1 回答 1

0

下面是如何使用新的 API 完成此操作。

// A List does hold the queries
List<FilterDefition<BsonDocument>> QueryConditionList = new List<FilterDefition<BsonDocument>>();

void AddQuery(string sType, string sField, string sValue)
{
    // I can add of course several Queries
    if (sType == "EQ")
        QueryConditionList.Add(Builders<BsonDocument>.Filter.Eq(sField, sValue));
    else if (sType == "GT")
        QueryConditionList.Add(Builders<BsonDocument>.Filter.Gt(sField, sValue));
    else if (sType == "LT")
        QueryConditionList.Add(Builders<BsonDocument>.Filter.Lt(sField, sValue));
}

Task ExecuteQueryAsync()
{
    // The And method takes an IEnumerable<FilterDefinition<BsonDocument>>.
    var filter = Builders<BsonDocument>.Filter.And(QueryConditionList);
    var results = await MoCollection.Find(query).ToListAsync();
}
于 2015-09-10T12:34:47.533 回答