AGGREGATE world - Revision history

40082593 at 14:55, 30 July 2015

2015-07-30T14:55:03Z

← Older revision		Revision as of 14:55, 30 July 2015
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	#PRETTY		#PRETTY
	import pprint		import pprint
	pp = pprint.PrettyPrinter(indent=4)		pp = pprint.PrettyPrinter(indent=4, width=160)
	</pre>		</pre>

2015-07-28T12:11:35Z

← Older revision		Revision as of 12:11, 28 July 2015
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	<div class=q data-lang="py3">		<div class=q data-lang="py3">
	Show the <b>name</b> and the <b>continent</b> - but ~~substitute~~ <b>~~Australasia~~</b> ~~for~~ <b>~~Oceania~~</b> ~~- for countries beginning with N~~.		Show the <b>name</b> and the <b>continent</b> for countries beginning with N - but replace the continent <b>Oceania</b> with <b>Australasia</b>.
	<pre class=def>		<pre class=def>
	pp.pprint(list(		pp.pprint(list(

2015-07-28T11:52:10Z

Harder Questions

← Older revision		Revision as of 11:52, 28 July 2015
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	pp.pprint(list(		pp.pprint(list(
	db.world.aggregate([		db.world.aggregate([
	{"$match":{"continent":"North America"}},		{"$match":{
			"continent":"North America"
			}},
	{"$project":{		{"$project":{
	"_id":0,		"_id":0,
	"name":1		"name":1
			}}
	])		])
	))		))

2015-07-28T11:50:11Z

← Older revision		Revision as of 11:50, 28 July 2015
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	Print a list of names for countries in the continent of "North America" change United States to USA		Print a list of names for countries in the continent of "North America" change United States to USA
	<pre class=def>		<pre class=def>
			pp.pprint(list(
			db.world.aggregate([
			{"$match":{"continent":"North America"}},
			{"$project":{
			"_id":0,
			"name":1
			])
			))
	</pre>		</pre>
	<div class=ans>		<div class=ans>
	pp.pprint(list(db.world.aggregate([{"$match":{"continent":"North America"}},{"$project":{"_id":0,"name" :{"$cond": [{"$eq":["$name","United States"]},"USA","$name"]}}}])))		pp.pprint(list(db.world.aggregate([{"$match":{"continent":"North America"}},{"$project":{"_id":0,"name":{"$cond": [{"$eq":["$name","United States"]},"USA","$name"]}}}])))
	</div>		</div>
	</div>		</div>

2015-07-28T11:41:49Z

Harder Questions

@@ Line 150: / Line 150: @@
 ==Harder Questions==
 <div class=q data-lang="py3">
-Using Conditions<br/><br/>
+Print a list of names for countries in the continent of "North America" change United States to USA
 <pre class=def>
 </pre>
 <div class=ans>
-pp.pprint(list(db.world.aggregate([{"$group":{"_id":{"$cond":[{"$eq":["$continent","Eurasia"]},"Europe","$continent"]},"area":{"$sum":"$area"}}},{"$sort":{"area":-1}},{"$project":{"_id":1,"area":1}}])))
+pp.pprint(list(db.world.aggregate([{"$match":{"continent":"North America"}},{"$project":{"_id":0,"name" :{"$cond": [{"$eq":["$name","United States"]},"USA","$name"]}}}])))
 </div>
 </div>

2015-07-28T10:40:28Z

← Older revision		Revision as of 10:40, 28 July 2015
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	</pre>		</pre>
	<div class=ans>		<div class=ans>
	pp.pprint(list(db.world.aggregate([{"$match":{"name":{"$in":['France','Germany','~~Brazil~~']},"population":{"$ne":None},"area":{"$ne":0}}},{"$project":{"_id":0,"name":1,"population density":{"$divide":["$population","$area"]}}}])))		pp.pprint(list(db.world.aggregate([{"$match":{"name":{"$in":['France','Germany','Italy']},"population":{"$ne":None},"area":{"$ne":0}}},{"$project":{"_id":0,"name":1,"population density":{"$divide":["$population","$area"]}}}])))
	</div>		</div>
	</div>		</div>

2015-07-28T09:38:21Z

← Older revision		Revision as of 09:38, 28 July 2015
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	</div>		</div>
	<div class="hint" title="Division by 0 error?">		<div class="hint" title="Division by 0 error?">
	~~<code>~~ Use a <code>$match</code>. <code>{"area":{"$ne":0}}</code>		Use a <code>$match</code>. <code>{"area":{"$ne":0}}</code>
	</div>		</div>
	<pre class=def>		<pre class=def>

2015-07-22T12:44:46Z

40166222 moved page AGGREGATE world (PyMongo) to AGGREGATE world over a redirect without leaving a redirect

← Older revision	Revision as of 12:44, 22 July 2015
(No difference)

2015-07-22T10:46:12Z

← Older revision		Revision as of 10:46, 22 July 2015
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	"_id":0,		"_id":0,
	"name":1,		"name":1,
	"density": {"$divide": [~~10000~~,"$area"]}		"density": {"$divide": ["$population","$area"]}
	}},		}},
	{"$match":{		{"$match":{

2015-07-21T13:27:42Z

← Older revision	Revision as of 13:27, 21 July 2015
(No difference)