RethinkDB grouping and defining output -

i have table contains documents similar this:

{ "title": "title 2", "content": "this far, no further!", "category": "fiction" } 

this query i'm using:

r.table('posts').group('title').map(lambda item:     {'items': item['title']} ).run()) 

this output:

{   "title 1" : [     {       "items" : "title 1"     },     {       "items" : "title 1"     }   ],   "title 2" : [     {       "items" : "title 2"     },     {       "items" : "title 2"     },     {       "items" : "title 2"     },     {       "items" : "title 2"     }   ],   "title 3" : [     {       "items" : "title 3"     }   ] } 

however output structure looks this:

{   "title 1" : {     "item_count" : 3,     "items" : [       {         "items" : "title 1"       },       {         "items" : "title 1"       },       {         "items" : "title 1"       }     ]   },   "title 2" : {     "item_count" : 2,     "items" : [       {         "items" : "title 2"       },       {         "items" : "title 2"       }     ]   },   "title 3" : {     "item_count" : 1,     "items" : [       {         "items" : "title 3"       }     ]   } } 

how create query result.

in order that, need map query after executing ungroup in it.

first, output of first query looks incorrect. rethinkdb doesn't wouldn't return object/dictionary after map operation, return array. output got query following:

[   {     "group":  "title 1" ,     "reduction": [       {         "items":  "title 1"       } ,       {         "items":  "title 1"       }     ]   } ,   {     "group":  "title 2" ,     "reduction": [       {         "items":  "title 2"       } ,       {         "items":  "title 2"       }     ]   } ,   ... ] 

if want property called items along count of how many items items property has, can following:

// javascript r.table('posts')  .group('title')  .map(function (item) {     return {       items: item('title')     }  })  .ungroup()  .map(function (row) {      return {       'title': row('group'),       'items': row('reduction'),       'count': row('reduction').count()     }   }) 

the result of query following:

[   {     "count": 2 ,     "items": [       {         "items":  "title 1"       },       {         "items":  "title 1"       }     ],     "title":  "title 1"     },   {     "count": 2 ,     "items": [       {         "items":  "title 2"       } ,       {         "items":  "title 2"       }     ] ,     "title":  "title 2"   },   ... ] 

if want turn query object/dictionary can call post it's title, can turn array of posts object, using r.object along r.args. complete query this:

// javascript r.table('posts')  .group('title')  .map(function (item) {     return {       items: item('title')     }  })  .ungroup()  .map(function (row) {     return {       'title': row('group'),       'items': row('reduction'),       'count': row('reduction').count()     }   })   .do(function (rows) {     return r.object(r.args(rows.concatmap(function (row) {       return [row('title'), row];     })));   }) 

the result of query this:

{   "title 1": {     "count": 2 ,     "items": [       {         "items":  "title 1"       } ,       {         "items":  "title 1"       }     ] ,     "title":  "title 1"   } ,   "title 2": {     "count": 2 ,     "items": [       {         "items":  "title 2"       } ,       {         "items":  "title 2"       }     ] ,     "title":  "title 2"   } ,   ... }