Mongodb 与sql 语句对照

此处用mysql中的sql语句做例子,C# 驱动用的是samus,也就是上文中介绍的第一种.

引入项目MongoDB.dll

//创建Mongo连接

  var mongo = new Mongo("mongodb://localhost");

  mongo.Connect();

  //获取一个数据库,如果没有会自动创建一个

  var db = mongo.GetDatabase("movieReviews");

  //创建一个列表,并为这个列表创建文档

  var movies = db.GetCollection("movies");

连接没问题之后,现在让我们用mysql 与mongodb的一些语句做下对比:

	MongoDB	Mysql
查询全部	movies.find(new Document())	SELECT * FROM movies
条件查询	movies.Find(new Document { { "title", "Hello Esr" } });	SELECT * FROM movies WHERE title= 'foobar'
查询数量	movies.Find(new Document { { "title", "测试2" } }).Documents.Count();	SELECT COUNT(*) FROM movies WHERE `title` = 'foobar'
数量范围查询	1, movies.Find(new Document().Add(" $// <![CDATA[ where", new Code("this.num > 50"))); 2, movies.Find(new Document().Add("num", new Document().Add(" // ]]>$ gt",50))); ( $// <![CDATA[ gt : > ; // ]]>$ gte : >= ; $// <![CDATA[ lt : < ; // ]]>$ lte : <= ; $// <![CDATA[ ne : !=) 3,movies.Find("this.num > 50"); 4,movies.Find(new Document().Add(" // ]]>$ where",new Code("function(x){ return this.num > 50};")));	select * from movies where num > 50
分页查询	movies.Find(new Document()).Skip(10).Limit(20);	SELECT * FROM movies  limit 10,20
查询排序语句	movies.Find(new Document()).Sort(new Document() { { "num", -1 } });	SELECT * FROM movies ORDER BY num DESC
查询指定字段	movies.Find(new Document().Add("num", new Document().Add("$gt", 50)), 10, 0, new Document() { { "title", 1 } });	select title from movies where num > 50
插入语句	movies.Insert(new Document() { { "title", "测试" }, { "resuleData", DateTime.Now } });	INSERT INOT movies (`title`, `reauleDate`) values ('foobar',25)
删除语句	movies.Remove(new Document() { { "title", "Hello Esr" } });	DELETE * FROM movies
更新语句	movies.Update(new Document() { { "title", "测试2" } }              , new Document() { { "title", "测试11111" } });	UPDATE movies SET `title` = ‘测试1111’ WHERE `title` = '测试1111'
Linq查询	(from item in db.GetCollection("movies").Linq()                        where ((string)item["title"]).StartsWith("Esr")                        select item);	select * from movies where title like ‘%Esr’

这里只举出了几个比较典型的例子,可以这么说,只要mysql可以完成的sql语句,在mongodb里面都可以实现.