使用c#对MongoDB进行查询(1)
1.BsonDocument对象 在MongoDB.Bson命名空间下存在一个BsonDocument类，它是MongoDB的文档对象，代表着MongoDB中不规则数据一条条实体模型。可以使用BsonDocument对不规则数据进行操作，这个类型继承了IEnumberable<>类，也就是说又将每一个实体模型看做一个集合，我们可以使用下标方式获取实体模型中的值 // // 摘要: // Gets or sets a value by position. // // 参数: // index: // The position. // // 返回结果: // The value. public override BsonValue this[int index] { get; set; } // // 摘要: // Gets or sets a value by name. // // 参数: // name: // The name. // // 返回结果: // The value. public override BsonValue this[string name] { get; set; } // // 摘要: // Gets the value of an element or a default value if the element is not found. // // 参数: // name: // The name of the element. // // defaultValue: // The default value to return if the element is not found. // // 返回结果: // Teh value of the element or a default value if the element is not found. [Obsolete("Use GetValue(string name, BsonValue defaultValue) instead.")] public virtual BsonValue this[string name, BsonValue defaultValue] { get; } 2.连接配置 //连接地址 private static string conn = "mongodb://192.168.11.51:40000"; //数据库名称 private static string dbName = "yan"; //集合名称 private static string colName = "Demo"; //连接服务端 static MongoClient client = new MongoClient(conn); //获取指定数据库 static IMongoDatabase db = client.GetDatabase(dbName); //获取指定集合 BsonDocument数据库文档对象 static IMongoCollection<BsonDocument> coll = db.GetCollection<BsonDocument>(colName); 3.插入数据 var doc = new[] { new BsonDocument{ { "DepartmentName","开发部"}, { "People",new BsonArray { new BsonDocument{ { "Name", "狗娃" },{"Age",20 } }, new BsonDocument{ { "Name", "狗剩" },{"Age",22 } }, new BsonDocument{ { "Name", "铁蛋" },{"Age",24 } } } }, {"Sum",18 }, { "dim_cm", new BsonArray { 14, 21 } } }, new BsonDocument{ { "DepartmentName","测试部"}, { "People",new BsonArray { new BsonDocument{ { "Name", "张三" },{"Age",11 } }, new BsonDocument{ { "Name", "李四" },{"Age",34 } }, new BsonDocument{ { "Name", "王五" },{"Age",33 } } } } , { "Sum",4 } , { "dim_cm", new BsonArray { 14, 21 } } }, new BsonDocument{ { "DepartmentName","运维部"}, { "People",new BsonArray { new BsonDocument{ { "Name", "闫" },{"Age",20 } }, new BsonDocument{ { "Name", "王" },{"Age",22 } }, new BsonDocument{ { "Name", "赵" },{"Age",24 } } } }, { "Sum",2 }, { "dim_cm", new BsonArray { 22.85, 30 } } } }; coll.InsertMany(doc); 4.查询 4.1 查询部门是开发部的信息 //创建约束生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; //约束条件 FilterDefinition<BsonDocument> filter = builder.Eq("DepartmentName", "开发部"); //获取数据 var result = coll.Find<BsonDocument>(filter).ToList(); foreach (var item in result) { //取出整条值 Console.WriteLine(item.AsBsonValue); } 4.2 获取Sum大于4的数据 //创建约束生成器 FilterDefinitionBuilder<BsonDocument> builderFIlter = Builders<BsonDocument>.Filter; //约束条件 FilterDefinition<BsonDocument> filter = builder.Gt("Sum", 4); var result = coll.Find<BsonDocument>(filter).ToList(); foreach (var item in result) { //取出整条值 Console.WriteLine(item.AsBsonValue); } 4.3 And约束 //创建约束生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; //约束条件 FilterDefinition<BsonDocument> filter = builder.And(builder.Gt("Sum", "2"), builder.Eq("DepartmentName", "运维")); var result = coll.Find<BsonDocument>(filter).ToList(); foreach (var item in result) { //取出整条值 Console.WriteLine(item.AsBsonValue); } 4.4查询指定值 //创建约束生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; ProjectionDefinitionBuilder<BsonDocument> builderProjection = Builders<BsonDocument>.Projection; //Include 包含某元素 Exclude 不包含某元素 ProjectionDefinition<BsonDocument> projection = builderProjection.Include("DepartmentName").Exclude("_id"); var result = coll.Find<BsonDocument>(builderFilter.Empty).Project(projection).ToList(); foreach (var item in result) { //取出整条值 Console.WriteLine(item.AsBsonValue); } 4.5 排序 //创建生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; //排序生成器 SortDefinitionBuilder<BsonDocument> builderSort = Builders<BsonDocument>.Sort; //排序约束 Ascending 正序 Descending 倒序 SortDefinition<BsonDocument> sort = builderSort.Ascending("Sum"); var result = coll.Find<BsonDocument>(builderFilter.Empty).Sort(sort).ToList(); foreach (var item in result) { //取出整条值 Console.WriteLine(item.AsBsonValue); } 4.6 In查询 //创建生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; FilterDefinition<BsonDocument> filter = builderFilter.In("DepartmentName", new[] { "测试部", "开发部" }); var result = coll.Find<BsonDocument>(filter).ToList(); foreach (var item in result) { //取出整条值 Console.WriteLine(item.AsBsonValue); } 4.7 分页查询 //创建生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; //分页 Skip 跳过 Limit查询多少 var result = coll.Find<BsonDocument>(builderFilter.Empty).Skip(1).Limit(1).ToList(); foreach (var item in result) { //取出整条值 Console.WriteLine(item.AsBsonValue); } 4.8查询总条目数 //创建生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; //总条目数 var result = coll.Find<BsonDocument>(builderFilter.Empty).Count(); 4.9Linq查询 //创建生成器//linq var result = from y in coll.AsQueryable() select new { DepartmentName = y["DepartmentName"], id = y["_id"] }; foreach (var item in result) { Console.WriteLine("DepartmentName:" + item.DepartmentName + "====Id:"+item.id); } 4.10分组查询 //创建生成器 FilterDefinitionBuilder<BsonDocument> builderFilter = Builders<BsonDocument>.Filter; //分组 var result = from y in coll.AsQueryable() group y by y["DepartmentName"] into s select new { DepartmentName = s.Key, Count = s.Count() }; foreach (var item in result) { Console.WriteLine("DepartmentName:" + item.DepartmentName + "====Count:"+item.Count); } 4.11连表查询 //linq //连表查询 在这里是自己连自己 var result = from u in coll.AsQueryable() join o in coll.AsQueryable() on u["_id"] equals o["_id"] select new { DepartmentName1 = u["DepartmentName"], DepartmentName2 = u["DepartmentName"] }; foreach (var item in result) { Console.WriteLine("DepartmentName1:" + item.DepartmentName1 + "====DepartmentName2:" + item.DepartmentName2); }
