MongoDB教程之查询操作实例
1. 基本查询:
构造查询数据。
>db.test.findOne() { "_id":ObjectId("4fd58ecbb9ac507e96276f1a"), "name":"stephen", "age":35, "genda":"male", "email":"stephen@hotmail.com" } --多条件查询。下面的示例等同于SQL语句的wherename="stephen"andage=35 >db.test.find({"name":"stephen","age":35}) {"_id":ObjectId("4fd58ecbb9ac507e96276f1a"),"name":"stephen","age":35,"genda":"male","email":"stephen@hotmail.com"} --返回指定的文档键值对。下面的示例将只是返回name和age键值对。 >db.test.find({},{"name":1,"age":1}) {"_id":ObjectId("4fd58ecbb9ac507e96276f1a"),"name":"stephen","age":35}
--指定不返回的文档键值对。下面的示例将返回除name之外的所有键值对。 >db.test.find({},{"name":0}) {"_id":ObjectId("4fd58ecbb9ac507e96276f1a"),"age":35,"genda":"male","email":"stephen@hotmail.com"}