Mongodb c#过滤器使用和或运算符答案

【问题标题】：Mongodb c# filter using and or operatorMongodb c#过滤器使用和或运算符
【发布时间】：2018-04-12 16:25:08
【问题描述】：

我在mongodb中有json文件

示例

{
 "SchemaName": "Intelligence",
 "SchemaDescription": "WindPower",
 "SchemaType": "WindPower",
 "SchemaTypeId": 1,
 "SchemaData": {
  "ProjectId": 1,
  "LastUpdated": "2016-07-02T19:27:28.000+0000",
  "ProjectName": "Zhonghuashan II",
  "Capacity": 49.0,
  "Technology": "Onshore",
   "Country":{
          "CountryId":1,
          "CountryName":"UnitedKingdom",
          "CountryCode":"UK"
    }
 }
}

现在我正在根据搜索条件过滤数据

var filter = Builders<Schema>.Filter.Or(
                Builders<Schema>.Filter.Where(p => p.SchemaData.ProjectName.ToLower().Contains(searchCriteria.ProjectName.ToLower())),
                Builders<Schema>.Filter.Where(p => p.SchemaData.Technology.ToLower().Contains(searchCriteria.Technology.ToLower())),
                Builders<Schema>.Filter.Where(p => p.SchemaData.Country.CountryName.ToLower().Contains(searchCriteria.Country.ToLower()))
            );
            var list = await collectionHandler.ReadOnly<Schema>().FindSync(filter).ToListAsync();
            return list;

我需要添加条件

searchCriteria.ProjectName ="" || searchCriteria.Technology="" || searchCriteria.Country = "" = return all records
searchCriteria.ProjectName ="abc" and searchCriteria.Technology="xyz" || searchCriteria.Country = "" = return matched records
searchCriteria.ProjectName ="abc" and searchCriteria.Technology="xyz" and searchCriteria.Country = "pqr" = return matched records
searchCriteria.ProjectName ="" || searchCriteria.Technology="xyz" and searchCriteria.Country = "pqr" = return matched records
searchCriteria.Technology="" ="abc" || searchCriteria.Technology="xyz" and searchCriteria.Country = "pqr" = return matched records

说搜索条件的任何属性都可以与搜索条件的其他属性结合使用 and 和 or

【问题讨论】：

标签： c# asp.net-mvc mongodb linq filter

【解决方案1】：

对我来说，我很乐意直接将过滤器作为字符串传递：

    FilterDefinition<BsonDocument> filter = @"{ ""Prop"": { $Or: [{ $and: [...] },{ $and: [...] }] } }";
    var lst = collection.Find(filter);

您可以查看文档：
https://docs.mongodb.com/v3.2/reference/operator/query/or/

【讨论】：

【解决方案2】：

我是这样做的：

将此答案作为here的基础

        var idFilter = new BsonDocument { { "_id", new BsonDocument { { "$regex", codeRegex }, { "$options", "i" } } } };
        var nameFilter = new BsonDocument { { "Name", new BsonDocument { { "$regex", codeRegex }, { "$options", "i" } } } };

        var filter = new BsonDocument("$or", new BsonArray { idFilter, nameFilter });

        var query = _collection.Find(filter)                
            .SortBy(c=>c.Id);
        return query.ToList();

【讨论】：