Difference between revisions of "Sort"
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<code>sort()</code> is a cursor method that orders the results of a query.<br/> | <code>sort()</code> is a cursor method that orders the results of a query.<br/> | ||
| − | The aggregation framework provides the <code>$sort</code> operator, and <code> | + | The aggregation framework provides the <code>$sort</code> operator, and <code>mapReduce</code> takes sort as a parameter that is applied to the input documents.<br/><br/> |
| − | The syntax for <code>sort()</code> is <code>sort(<field>:<value>)</code> where 1 indicates ascending and -1 indicates descending.<br/> | + | The syntax for <code>sort()</code> is <code>sort({<field>:<value>, <field>:<value>, ...})</code> where '''1''' indicates ascending and '''-1''' indicates descending.<br/> |
The order in which fields are specified dictates which fields are sorted first.<br/><br/> | The order in which fields are specified dictates which fields are sorted first.<br/><br/> | ||
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| − | <div class="q nonum" data-lang=" | + | <div class="q nonum" data-lang="mongo">Sort all the documents in world by continent descending, then name ascending. Show only name and continent. |
| − | <pre class=def> | + | <pre class="def"><nowiki>db.world.find({}, {name: 1, continent: 1 ,_id: 0}).sort({"continent": -1, "name": 1});</nowiki></pre> |
| − | db.world.find({},{name:1,continent:1,_id:0}).sort( | ||
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| − | </pre> | ||
</div> | </div> | ||
Latest revision as of 17:38, 18 July 2018
sort() is a cursor method that orders the results of a query.
The aggregation framework provides the $sort operator, and mapReduce takes sort as a parameter that is applied to the input documents.
The syntax for sort() is sort({<field>:<value>, <field>:<value>, ...}) where 1 indicates ascending and -1 indicates descending.
The order in which fields are specified dictates which fields are sorted first.
Sort all the documents in world by continent descending, then name ascending. Show only name and continent.
db.world.find({}, {name: 1, continent: 1 ,_id: 0}).sort({"continent": -1, "name": 1});