Introduction to MongoDB for Java, PHP and Python Developers

jieforest · 发表于 2012-6-8 06:14

Here is the complete PHP listing.

PHP complete listing

<!--?php
$m = new Mongo();
$db = $m->selectDB("tutorial");
$employees = $db->selectCollection("employees");
$cursor = $employees->find();
foreach ($cursor as $employee) {
echo var_export ($employee, true) . "< br />";
}
$cursor=$employees->find( array( "name" => "Rick Hightower"));
echo "Rick? < br /> " . var_export($cursor->getNext(), true);
$cursor=$employees->find(array("age" => array('$lt' => 35)));
echo "Diana? < br /> " . var_export($cursor->getNext(), true);
$cursor=$employees->find(array("_id" => new MongoId("4f984cce72320612f8f432bb")));
echo "Diana by id? < br /> " . var_export($cursor->getNext(), true);
?>

复制代码

If you like Object mapping to documents you should try the poorly named MongoLoid for PHP.

jieforest · 发表于 2012-6-8 06:16

Additional shell commands, learning about MongoDB via the console

One of the nice things that I appreciate about MongoDB, that is missing from some other NoSQL implementation, is getting around and finding information with the console application. They seem to closely mimic what can be done in MySQL so if you are familiar with MySQL, you will feel fairly at home in the mongo console.

To list all of the databases being managed by the mongod instance, you would do the following:

> show dbs
local (empty)
tutorial 0.203125GB

复制代码

To list the collections being managed by a database you could do this:

> show collections
employees
system.indexes

复制代码

To show a list of users, you do the following:

> show users

复制代码

To look at profiling and logging, you do this:

> show profile
db.system.profile is empty
Use db.setProfilingLevel(2) will enable profiling
..
> show logs
global
> show log global
Mon Apr 23 23:33:14 [initandlisten] MongoDB starting :
pid=11773 port=27017 dbpath=/etc/mongodb/data 64-bit…
…
Mon Apr 23 23:33:14 [initandlisten] options:
{ config: "/etc/mongodb/mongodb.config", dbpath: "/etc/mongodb/data" }

复制代码

jieforest · 发表于 2012-6-9 02:09

Also the commands and JavaScript functions themselves have help associated with them. To see all of the operations that DBCollection supports you could do this:

> db.employees.help()
DBCollection help
db.employees.find().help() - show DBCursor help
db.employees.count()
db.employees.dataSize()
db.employees.distinct( key ) - eg. db.employees.distinct( 'x' )
db.employees.drop() drop the collection
db.employees.dropIndex(name)
db.employees.dropIndexes()
db.employees.ensureIndex(keypattern[,options]) - options is an object with these possible fields: name, unique, dropDups
db.employees.reIndex()
db.employees.find([query],[fields]) - query is an optional query filter. fields is optional set of fields to return.
e.g. db.employees.find( {x:77} , {name:1, x:1} )
db.employees.find(...).count()
db.employees.find(...).limit(n)
db.employees.find(...).skip(n)
db.employees.find(...).sort(...)
db.employees.findOne([query])
db.employees.findAndModify( { update : ... , remove : bool [, query: {}, sort: {}, 'new': false] } )
db.employees.getDB() get DB object associated with collection
db.employees.getIndexes()
db.employees.group( { key : ..., initial: ..., reduce : ...[, cond: ...] } )
db.employees.mapReduce( mapFunction , reduceFunction , {optional params=""} )
db.employees.remove(query)
db.employees.renameCollection( newName , {droptarget} ) renames the collection.
db.employees.runCommand( name , {options} ) runs a db command with the given name where the first param is the collection name
db.employees.save(obj)
db.employees.stats()
db.employees.storageSize() - includes free space allocated to this collection
db.employees.totalIndexSize() - size in bytes of all the indexes
db.employees.totalSize() - storage allocated for all data and indexes
db.employees.update(query, object[, upsert_bool, multi_bool])
db.employees.validate( {full} ) – SLOW
db.employees.getShardVersion() - only for use with sharding
db.employees.getShardDistribution() - prints statistics about data distribution in the cluster ...

复制代码

jieforest · 发表于 2012-6-9 02:09

Just to show a snake eatings its own tail, you can even get help about help as follows:

> help
db.help() help on db methods
db.mycoll.help() help on collection methods
rs.help() help on replica set methods
help admin administrative help
help connect connecting to a db help
help keys key shortcuts
help misc misc things to know
help mr mapreduce
> help
…
show dbs show database names
show collections show collections in current database
show users show users in current database
show profile show most recent system.profile entries time>= 1ms
show logs show the accessible logger names
show log [name] prints out the last segment of log in memory,

复制代码

The MongoDB console reminds me of a cross between the MySQL console and Python's console. Once you use the console, it is hard to imagine using a NoSQL solution that does not have a decent console (hint, hint).

jieforest · 发表于 2012-6-9 02:10

Conclusion

The poorly named NoSQL movement seems to be here to stay. The need to have reliable storage that can be easily queried without the schema migration pain and scalability woes of traditional RDBMS is increasing. Developers want more agile systems without the pain of schema migration. MongoDB is a good first step for developers dipping their toe into the NoSQL solution space. It provides easy to use tools like its console and provides many language drivers. This article covered the basics of MongoDB architecture, caveats and how to program in MongoDB for Java, PHP, JavaScript and Python developers.

I hope you enjoyed reading this article 1/2 as much as I enjoyed writing it. --Rick Hightower

Introduction to MongoDB for Java, PHP and Python Developers

浏览过的版块