sort排序是对结果按照条件排序
数据结构如下图
查询语句:
db.posts.mapReduce(function(){ emit(this.num,this.post_text)}, function(key,values){return values.join("# ")}, { sort:{user_name:-1}, query:{status:"active"}, out:"test" } ) db.test.find()
结果:
查询语句:
db.posts.mapReduce(function(){
emit(this.num,this.post_text)},
function(key,values){return values.join("# ")},
{
sort:{user_name:1},
query:{status:"active"},
out:"test"
}
)
db.test.find()
数据库添加语句
db.getCollection("posts").insert( {
"post_text": "菜鸟教程6",
"user_name": "runoob",
status: "active",
num: 16
} );