Get schema information in MongoDB
Posted By : Akash Sharma | 01-May-2013
In this blog I am going to share the steps for getting information of schema of a collection.
Let say we have a collection named “posts” and we want to get names of fiels in all documents in that collection.
> mr = db.runCommand({ "mapreduce" : "posts", "map" : function() { for (var key in this) { emit(key, null); } },"reduce" : function(key, stuff) { return null; } , "out": "posts" + "_keys"});
{
"result" : "posts_keys",
"timeMillis" : 441,
"counts" : {
"input" : 1000,
"emit" : 8000,
"reduce" : 80,
"output" : 8
},
"ok" : 1
}
> db[mr.result].distinct("_id")
[
"_id",
"author",
"body",
"comments",
"date",
"permalink",
"tags",
"title"
]
>
The output of second command gives names of all fields in “posts” collection.
Akash Sharma
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About Author
Akash Sharma
Akash is a bright Groovy and Grails developer and have worked on development of various SaaS applications using Grails technologies. Akash loves playing Cricket and Tennis