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"}