FIND Examples - Revision history

40166222 at 14:12, 17 October 2018

2018-10-17T14:12:45Z

40166222: 40166222 moved page FIND examples to FIND Examples

2018-10-17T13:57:32Z

40166222 moved page FIND examples to FIND Examples

← Older revision	Revision as of 13:57, 17 October 2018
(No difference)

40166222: /* skip and limit */

2018-06-22T08:44:02Z

skip and limit

← Older revision		Revision as of 08:44, 22 June 2018
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	==skip and limit==		==skip and limit==
	<div class="q" data-lang="mongo">		<div class="q" data-lang="mongo">
	It is also possible to ~~specify which~~ document ~~to find by~~ its position.		It is also possible to retrieve a specific document based on its position using <code>skip(n-1)</code> and <code>limit(1)</code>.<br/>
	<~~div~~>~~You can achieve the same with~~ skip() and limit()</~~div~~>		As this is JavaScript you can also access by index: <code>db.world.find()[n-1];</code>
	<~~pre~~><~~nowiki~~>db.world.find()~~.skip(49).limit(~~1~~)</nowiki>~~</~~pre~~>
	<p class="strong">Get the 50th document of world</p>		<p class="strong">Get the 50th document of world</p>
	<pre class="def"><nowiki>db.world.find()[49];</nowiki></pre>		<pre class="def"><nowiki>db.world.find().skip(49).limit(1);</nowiki></pre>
	</div>		</div>

40166222: /* Introducing the world collection of countries */

2018-06-21T19:50:54Z

Introducing the world collection of countries

← Older revision		Revision as of 19:50, 21 June 2018
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	By default, <code>find()</code> returns the entire contents of a collection. This is equivalent to <code>find({})</code>		By default, <code>find()</code> returns the entire contents of a collection. This is equivalent to <code>find({})</code>
	<p class="strong">Show all the documents in world</p>		<p class="strong">Show all the documents in world</p>
	<pre class="def"><nowiki>db.world.find();</nowiki><</pre>		<pre class="def"><nowiki>db.world.find();</nowiki></pre>
	</div>		</div>

40166222 at 19:50, 21 June 2018

2018-06-21T19:50:32Z

← Older revision		Revision as of 19:50, 21 June 2018
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	By default, <code>find()</code> returns the entire contents of a collection. This is equivalent to <code>find({})</code>		By default, <code>find()</code> returns the entire contents of a collection. This is equivalent to <code>find({})</code>
	<p class="strong">Show all the documents in world</p>		<p class="strong">Show all the documents in world</p>
	<pre class="def">db.world.find()</pre>		<pre class="def"><nowiki>db.world.find();</nowiki><</pre>
	</div>		</div>

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	It is also possible to just return the first document with <code>findOne()</code>.		It is also possible to just return the first document with <code>findOne()</code>.
	<p class="strong">Show the first document of world</p>		<p class="strong">Show the first document of world</p>
	<pre class="def"><nowiki>db.world.findOne()</nowiki></pre>		<pre class="def"><nowiki>db.world.findOne();</nowiki></pre>
	</div>		</div>

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	<pre><nowiki>db.world.find().skip(49).limit(1)</nowiki></pre>		<pre><nowiki>db.world.find().skip(49).limit(1)</nowiki></pre>
	<p class="strong">Get the 50th document of world</p>		<p class="strong">Get the 50th document of world</p>
	<pre class="def"><nowiki>db.world.find()[49]</nowiki></pre>		<pre class="def"><nowiki>db.world.find()[49];</nowiki></pre>
	</div>		</div>

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	<code>find()</code> can filter results if a document is used as an argument.		<code>find()</code> can filter results if a document is used as an argument.
	<p class="strong">Get all the data concerning france</p>		<p class="strong">Get all the data concerning france</p>
	<pre class="def"><nowiki>db.world.findOne({"name":"France"})</nowiki></pre>		<pre class="def"><nowiki>db.world.findOne({"name":"France"});</nowiki></pre>
	</div>		</div>

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	This is a unique ID MongoDB adds to each document. Unlike other keys, it has to be <b>explicitly</b> set to false to be excluded from the results set.<br/>		This is a unique ID MongoDB adds to each document. Unlike other keys, it has to be <b>explicitly</b> set to false to be excluded from the results set.<br/>
	<p class="strong">Get the population of Germany</p>		<p class="strong">Get the population of Germany</p>
	<pre class="def"><nowiki>db.world.findOne({"name":"Germany"},{"population":1,"_id":0})</nowiki></pre>		<pre class="def"><nowiki>db.world.findOne({"name": "Germany"},{"population": 1,"_id": 0});</nowiki></pre>
	</div>		</div>

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	</pre>		</pre>
	<p class="strong">List the countries with a population that's less than 1 million.</p>		<p class="strong">List the countries with a population that's less than 1 million.</p>
	<pre class="def"><nowiki>db.world.find({"population": {"$lt": 1000000}}, {"name": 1,"_id": 0})</nowiki></pre>		<pre class="def"><nowiki>db.world.find({"population": {"$lt": 1000000}}, {"name": 1,"_id": 0});</nowiki></pre>
	</div>		</div>

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	<nowiki>		<nowiki>
	AND (implicit)		AND (implicit)
	db.<collection>.find({<first condition>,<second condition>})		db.<collection>.find({<first condition>,<second condition>});
	db.world.find({"population":{"$lt":1000000},"area":{"$gt":200000}})		db.world.find({"population":{"$lt":1000000},"area":{"$gt":200000}});

	AND (explicit)		AND (explicit)
	db.<collection>.find({"$and":[<first condition>,<second condition>]})		db.<collection>.find({"$and":[<first condition>,<second condition>]});
	db.world.find({"$and":[{"population":{"$lt":1000000}},{"area":{"$gt":200000}}]})		db.world.find({"$and":[{"population":{"$lt":1000000}},{"area":{"$gt":200000}}]});

	OR		OR
	db.<collection>.find({"$or":[<first condition>,<second condition>]})		db.<collection>.find({"$or":[<first condition>,<second condition>]});
	db.world.find({"$or":[{"population":{"$lt":1000000}},{"area":{"$gt":200000}}]})		db.world.find({"$or":[{"population":{"$lt":1000000}},{"area":{"$gt":200000}}]});
	</nowiki>		</nowiki>
	</pre>		</pre>

	<p class="strong">Find the countries with less than 1 million people, but over 200000km<sup>2</sup> area.</p>		<p class="strong">Find the countries with less than 1 million people, but over 200000km<sup>2</sup> area.</p>
	<pre class="def"><nowiki>db.world.find({"population":{"$lt":1000000},"area":{"$gt":200000}},{"name":1,"_id":0})</nowiki></pre>		<pre class="def"><nowiki>db.world.find({"population": {"$lt": 1000000},"area": {"$gt": 200000}},{"name": 1,"_id": 0});</nowiki></pre>
	</div>		</div>

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	Lists can be used with <code>$in</code> and <code>$nin</code>:		Lists can be used with <code>$in</code> and <code>$nin</code>:
	<p class="strong">Find the continent of Brazil, the United Kingdom, and Ghana.</p>		<p class="strong">Find the continent of Brazil, the United Kingdom, and Ghana.</p>
	<pre class="def">		<pre class="def"><nowiki>
	<nowiki>
	db.world.find(		db.world.find(
	{name: {$in: ['Brazil', 'Ghana', 'United Kingdom']}},		{name: {$in: ['Brazil', 'Ghana', 'United Kingdom']}},
	{name: 1, continent: 1, _id: 0}		{name: 1, continent: 1, _id: 0}
	)		);</nowiki></pre>
	</nowiki>
	</pre>
	</div>		</div>

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	Pattern matching is possible with Regular Expressions (RegEx)<br/>		Pattern matching is possible with Regular Expressions (RegEx)<br/>
	<p class="strong">Show each country that begins with G</p> [https://no.sqlzoo.net/wiki/RegEx_Pattern_Matching Reference]		<p class="strong">Show each country that begins with G</p> [https://no.sqlzoo.net/wiki/RegEx_Pattern_Matching Reference]
	<pre class="def">		<pre class="def"><nowiki>
	<nowiki>
	db.world.find(		db.world.find(
	{name: {$regex: /^G/}},		{name: {$regex: /^G/}},
	{name: 1, continent: 1, _id: 0}		{name: 1, continent: 1, _id: 0}
	)		);</nowiki></pre>
	</nowiki>
	</pre>
	</div>		</div>

40166222 at 09:31, 15 June 2018

2018-06-15T09:31:44Z

← Older revision		Revision as of 09:31, 15 June 2018
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	It is also possible to just return the first document with <code>findOne()</code>.		It is also possible to just return the first document with <code>findOne()</code>.
	<p class="strong">Show the first document of world</p>		<p class="strong">Show the first document of world</p>
	<pre class="def">db.world.findOne()</pre>		<pre class="def"><nowiki>db.world.findOne()</nowiki></pre>
	</div>		</div>

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	It is also possible to specify which document to find by its position.		It is also possible to specify which document to find by its position.
	<div>You can achieve the same with skip() and limit()</div>		<div>You can achieve the same with skip() and limit()</div>
	<pre>		<pre><nowiki>db.world.find().skip(49).limit(1)</nowiki></pre>
	db.world.find().skip(49).limit(1)
	</pre>
	<p class="strong">Get the 50th document of world</p>		<p class="strong">Get the 50th document of world</p>
	<pre class="def">db.world.find()[49]</pre>		<pre class="def"><nowiki>db.world.find()[49]</nowiki></pre>
	</div>		</div>

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	<code>find()</code> can filter results if a document is used as an argument.		<code>find()</code> can filter results if a document is used as an argument.
	<p class="strong">Get all the data concerning france</p>		<p class="strong">Get all the data concerning france</p>
	<pre class="def">db.world.findOne({"name":"France"})</pre>		<pre class="def"><nowiki>db.world.findOne({"name":"France"})</nowiki></pre>
	</div>		</div>

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	This is a unique ID MongoDB adds to each document. Unlike other keys, it has to be <b>explicitly</b> set to false to be excluded from the results set.<br/>		This is a unique ID MongoDB adds to each document. Unlike other keys, it has to be <b>explicitly</b> set to false to be excluded from the results set.<br/>
	<p class="strong">Get the population of Germany</p>		<p class="strong">Get the population of Germany</p>
	<pre class="def">db.world.findOne({"name":"Germany"},{"population":1,"_id":0})</pre>		<pre class="def"><nowiki>db.world.findOne({"name":"Germany"},{"population":1,"_id":0})</nowiki></pre>
	</div>		</div>

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	MongoDB also allows comparisons. Syntax:		MongoDB also allows comparisons. Syntax:
	<pre>		<pre>
			<nowiki>
	Mongo \| MySQL		Mongo \| MySQL
	--------------		--------------
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	$in \| IN		$in \| IN
	$nin \| NOT IN		$nin \| NOT IN
			</nowiki>
	</pre>		</pre>
	<p class="strong">List the countries with a population that's less than 1 million.</p>		<p class="strong">List the countries with a population that's less than 1 million.</p>
	<pre class="def">db.world.find({"population":{"$lt":1000000}},{"name":1,"_id":0})</pre>		<pre class="def"><nowiki>db.world.find({"population": {"$lt": 1000000}}, {"name": 1,"_id": 0})</nowiki></pre>
	</div>		</div>

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	It's also possible to have multiple conditions for use in an <code>$and</code>, <code>$or</code>, etc. This can be done in several ways, for example:		It's also possible to have multiple conditions for use in an <code>$and</code>, <code>$or</code>, etc. This can be done in several ways, for example:
	<pre>		<pre>
			<nowiki>
	AND (implicit)		AND (implicit)
	db.<collection>.find({<first condition>,<second condition>})		db.<collection>.find({<first condition>,<second condition>})
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	db.<collection>.find({"$or":[<first condition>,<second condition>]})		db.<collection>.find({"$or":[<first condition>,<second condition>]})
	db.world.find({"$or":[{"population":{"$lt":1000000}},{"area":{"$gt":200000}}]})		db.world.find({"$or":[{"population":{"$lt":1000000}},{"area":{"$gt":200000}}]})
			</nowiki>
	</pre>		</pre>

	<p class="strong">Find the countries with less than 1 million people, but over 200000km<sup>2</sup> area.</p>		<p class="strong">Find the countries with less than 1 million people, but over 200000km<sup>2</sup> area.</p>
	<pre class="def">db.world.find({"population":{"$lt":1000000},"area":{"$gt":200000}},{"name":1,"_id":0})</pre>		<pre class="def"><nowiki>db.world.find({"population":{"$lt":1000000},"area":{"$gt":200000}},{"name":1,"_id":0})</nowiki></pre>
	</div>		</div>

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	<p class="strong">Find the continent of Brazil, the United Kingdom, and Ghana.</p>		<p class="strong">Find the continent of Brazil, the United Kingdom, and Ghana.</p>
	<pre class="def">		<pre class="def">
			<nowiki>
	db.world.find(		db.world.find(
	{name:{$in:['Brazil','Ghana','United Kingdom']}},		{name: {$in: ['Brazil', 'Ghana', 'United Kingdom']}},
	{name:1,continent:1,_id:0}		{name: 1, continent: 1, _id: 0}
	)		)
			</nowiki>
	</pre>		</pre>
	</div>		</div>
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	<p class="strong">Show each country that begins with G</p> [https://no.sqlzoo.net/wiki/RegEx_Pattern_Matching Reference]		<p class="strong">Show each country that begins with G</p> [https://no.sqlzoo.net/wiki/RegEx_Pattern_Matching Reference]
	<pre class="def">		<pre class="def">
			<nowiki>
	db.world.find(		db.world.find(
	{name:{$regex:/^G/}},		{name: {$regex: /^G/}},
	{name:1,continent:1,_id:0}		{name: 1, continent: 1, _id: 0}
	)		)
			</nowiki>
	</pre>		</pre>
	</div>		</div>

40166222: /* Comparisons $eq $gt $gte $lte $ne */

2018-06-13T08:41:40Z

Comparisons $eq $gt $gte $lte $ne

← Older revision		Revision as of 08:41, 13 June 2018
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	</div>		</div>

	==Comparisons $eq %gt $gte $lte $ne==		==Comparisons $eq $gt $gte $lte $ne==
	<div class="q" data-lang="mongo">		<div class="q" data-lang="mongo">
	MongoDB also allows comparisons. Syntax:		MongoDB also allows comparisons. Syntax:

40166222 at 00:27, 9 April 2018

2018-04-09T00:27:45Z

← Older revision		Revision as of 00:27, 9 April 2018
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	<div class="q" data-lang="mongo">		<div class="q" data-lang="mongo">
	Pattern matching is possible with Regular Expressions (RegEx)<br/>		Pattern matching is possible with Regular Expressions (RegEx)<br/>
	<p class="strong">Show each country that begins with G</p> [~~http~~://no.sqlzoo.net/wiki/RegEx_Pattern_Matching Reference]		<p class="strong">Show each country that begins with G</p> [https://no.sqlzoo.net/wiki/RegEx_Pattern_Matching Reference]
	<pre class="def">		<pre class="def">
	db.world.find(		db.world.find(

40166222: /* Regular Expressions */

2018-04-09T00:27:08Z

Regular Expressions

← Older revision		Revision as of 00:27, 9 April 2018
Line 98:		Line 98:
	<div class="q" data-lang="mongo">		<div class="q" data-lang="mongo">
	Pattern matching is possible with Regular Expressions (RegEx)<br/>		Pattern matching is possible with Regular Expressions (RegEx)<br/>
	<p class="strong">Show each country that begins with G</p> [http://no.sqlzoo.net/wiki/~~Regex_Pattern_Matching~~ Reference]		<p class="strong">Show each country that begins with G</p> [http://no.sqlzoo.net/wiki/RegEx_Pattern_Matching Reference]
	<pre class="def">		<pre class="def">
	db.world.find(		db.world.find(

40166222: /* Regular Expressions */

2018-04-09T00:26:22Z

Regular Expressions

← Older revision		Revision as of 00:26, 9 April 2018
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	<div class="q" data-lang="mongo">		<div class="q" data-lang="mongo">
	Pattern matching is possible with Regular Expressions (RegEx)<br/>		Pattern matching is possible with Regular Expressions (RegEx)<br/>
	<p class="strong">Show each country that begins with G</p>		<p class="strong">Show each country that begins with G</p> [http://no.sqlzoo.net/wiki/Regex_Pattern_Matching Reference]
	[~~[RegEx_Pattern_Matching]~~]
	<pre class="def">		<pre class="def">
	db.world.find(		db.world.find(