Basic usage tutorial of mongodb BSON
Find Find
M: = bson.M {"create_time": bson.M {"$gte": start, "$lte": end,}, "account": account, "tag": "tag",} session.DB ("db"). C ("collect") .Find (m). Count ()
Find the data in the timestamp with the account number of account and the label of tag and count the number.
The aggregation pipeline is Pipe (pipeline interface {}) in mgo
This is similar to the pipes used in bash, where data can be processed layer by layer. Generally, the parameter passed is [] bson.M. If there is any nesting in this [] bson.M, you need to use [] bson.M.
-for example, the tag and account number are matched first.
-timestamp over a period of time
-then count the number in groups by name.
-the first three are taken in the final sort.
/ / this can be passed in Pipe m: = [] bson.M {{"$match": bson.M {"tag": "tag", "account": account, "create_time": bson.M {"$gte": start, "$lte": end}, {"$group": bson.M {"_ id": "$TagName", "count": bson.M {"$sum": 1} {"$sort": bson.M {"count":-1}}, {"$limit": 3},} / / you can get the output data var values [] result session.DB ("db"). C ("collect") .pipe (m). Pipe (& values)
A brief introduction
Package mainimport ("gopkg.in/mgo.v2"log"gopkg.in/mgo.v2/bson") type User struct {Id bson.ObjectId `bson: "_ id" `Name string `bson: "name" `PassWord string `bson: "pass_word" `Age int `bson: "age"`} func main () {db Err: = mgo.Dial ("mongodb://192.168.2.28:27017192.168.2.28:27018192.168.2.28:27019/?replicaSet=howie") if err! = nil {log.Fatalln (err)} defer db.Close () db.SetMode (mgo.Monotonic, true) c: = db.DB ("howie"). C ("person") / / insert / * c.Insert (& User {Id: bson.NewObjectId (), Name: "JK_CHENG", PassWord: "123132" Age: 2,}, & User {Id: bson.NewObjectId (), Name: "JK_WEI", PassWord: "qwer", Age: 5,}, & User {Id: bson.NewObjectId (), Name: "JK_HE", PassWord: "6666", Age: 7 }) * / var users [] User c.Find (nil). All (& users) / / query all data log.Println (users) c.FindId (users [0] .ID). All (& users) / / query log.Println (users) c.Find (bson.M {"name": "JK_WEI"}) through ID. All (& users) / / single condition query (=) log.Println (users) c.Find (bson.M {" Name ": bson.M {" $ne ":" JK_WEI "}). All (& users) / / single conditional query (! =) log.Println (users) c.Find (bson.M {" age ": bson.M {" $gt ": 5}}). All (& users) / / single conditional query (>) log.Println (users) c.Find (bson.M {" age ": bson.M {" $gte ": 5}}). All (& users) ) / / single conditional query (> =) log.Println (users) c.Find (bson.M {"age": bson.M {"$lt": 5}}) .All (& users) / / single conditional query (
