[mongod@localhost ~]$
mongo test
MongoDB shell version:
3.2.6
connecting to: test
> db.mycol.drop()
False
>
db.mycol.insert({'_id':1,x:1,y:2,z:3})
WriteResult({
"nInserted" : 1 })
> db.mycol.insert({'_id':3,y:2,z:3,x:1})
WriteResult({
"nInserted" : 1 })
>
db.mycol.find().pretty()
{ "_id" : 1,
"x" : 1, "y" : 2, "z" : 3 }
{ "_id" : 3,
"y" : 2, "z" : 3, "x" : 1 }
>
db.mycol.createIndex({x:1,y:1,z:1},{unique:true})
{
"ok" : 0,
"errmsg" : "E11000
duplicate key error collection: test.mycol index: x_1_y_1_z_1 dup key: { : 1.0,
: 2.0, : 3.0 }",
"code" : 11000
}
>
db.mycol.find({x:1,y:2,z:3})
{ "_id" : 1,
"x" : 1, "y" : 2, "z" : 3 }
{ "_id" : 3,
"y" : 2, "z" : 3, "x" : 1 }
>
db.mycol.find({x:1,y:2,z:3},{x:1,y:1,z:1})
{ "_id" : 1,
"x" : 1, "y" : 2, "z" : 3 }
{ "_id" : 3,
"y" : 2, "z" : 3, "x" : 1 }
// some proper formatting by re-arranging the column/key
names
>
db.mycol.aggregate([{$match:{x:1,y:2,z:3}},{$project:{xx:"$x",yy:"$y",zz:"$z"}},{$project:{x:"$xx",y:"$yy",z:"$zz"}}])
{ "_id" : 1,
"x" : 1, "y" : 2, "z" : 3 }
{ "_id" : 3,
"x" : 1, "y" : 2, "z" : 3 }
