MONGDB Shell Scripting Learning

Just started contacting the mongdb shell. Here is a record of the learning process.

Open the shell in the console.

Linux Environment:/usr/local/mongo/bin/mongo

Window Environment: D:\mongodb\mongodb-win32-i386-2.0.6\bin>mongo

The basic section can be consulted: http://www.cnblogs.com/anan/archive/2012/06/15/2550553.html

First create a JS function

function query () {
print ("Start execution--------------");
Query a table Video_encode
var encode_coll=db.video_encode.find ({status:{"$lt": Ten});
Print (Encode_coll.count ());//number of prints
//loop variable while
(Encode_coll.hasnext ()) {
var v=encode_coll.next ();
Print (v.name);//Printing Properties
} print
("End Execution--------------");
}

Call the query () method directly to execute. Figure below

This function is primarily used to query records from a table based on criteria, and then iterate through the records to print.

Note When you first start learning, you encounter such a question.

In getting a collection how do I know how to manipulate this set such as Var encode_coll=db.video_encode.find ();

How to know this object.

You can actually know his internal structure by traversing the object.

For example:

for (var param in encode_coll) {

print (param);

You will see the properties of the returned cursor as shown here:

Obviously this is the encapsulation of the MONGDB internal to the Db.find () return object, so we can do better.

Here's an example:

I have two tables: Video_uplaod (uploadid,size), Transcode_job (id,uploadid,act)

I want to count the size of act = "CLOUD" for all files.

The idea is to first isolate all uploadids (arrays) from the table transcode_job according to act = "CLOUD".

In accordance with Uploadids, all sizes are counted from the table video_upload.

As shown in figure:

。

Statistical transcoding failure Rate

function Fun_encode_fail () {//Statistical time period, transcoding failure rate var b_time=new date (2012,05,01);//2012-06-01 var e_time=new date (2012,06,01) ;//2012-02-01 var temp_time=new Date (2012,05,01);//Temporary Time B_time.setdate (B_time.getdate () +7);

Add seven days//cycle add date var weeks=0;
		Statistics for the specified time class, transcoding failure rate function Failrate (starttime,endtime) {print ("StartTime:" +starttime+ "EndTime:" +endtime); var count=0;//number of transcoding var retrytimes=0;//failures var fail_rate=0;//failure rate//query is the query condition, is the JSON object var query={"status": {"$in": [
		20,30,70,-100,-101,-200]}, "Createtime": {"$gt": StartTime, "$lte": EndTime}};
		var cusor_encode=db.video_encode.find (query);
var cusor_history=db.video_encode_history.find (query);
			  Loop Cusor_encode while (Cusor_encode.hasnext ()) {var video=cusor_encode.next ();
			  if (video.retrytimes>0) {retrytimes+=video.retrytimes;
			} count++;
			  }//Loop cusor_history while (Cusor_history.hasnext ()) {var video=cusor_history.next ();
			  if (video.retrytimes>0) {retrytimes+=video.retrytimes;} count++;
		} fail_rate=count+retrytimes==0?0:retrytimes/(Count+retrytimes);
		Print ("Number of transcoding:" +count);
		Print ("Number of failures:" +retrytimes);
		Print ("Failure rate:" +fail_rate); var fail_rate_json={"Week": Weeks, "startTime": StartTime, "EndTime": EndTime, "transcodenums": Count, "Failtimes":
		Retrytimes, "Failrate": fail_rate};
	Db.fail_rate_info.insert (Fail_rate_json);
	}//Initialization table Fail_rate_info Db.fail_rate_info.remove ();
		while (b_time<e_time) {print ("+ (++weeks) +" Week "); Failrate (Temp_time.gettime (), B_time.gettime ());
		The function needs to be declared in advance temp_time.setdate (Temp_time.getdate () +7);
	B_time.setdate (B_time.getdate () +7); }
}