From 305dc2776a51831757b7326bc670878835709b73 Mon Sep 17 00:00:00 2001 From: Louis Chatriot Date: Sun, 26 Jan 2014 13:53:20 +0100 Subject: [PATCH] Update README.md --- README.md | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/README.md b/README.md index 0256902..237aeaf 100644 --- a/README.md +++ b/README.md @@ -145,6 +145,8 @@ Use `find` to look for multiple documents matching you query, or `findOne` to lo You can use regular expressions in two ways: in basic querying in place of a string, or with the `$regex` operator. +You can sort and paginate results using the cursor API (see below). + #### Basic querying Basic querying means are looking for documents whose fields match the ones you specify. You can use regular expression to match strings. You can use the dot notation to navigate inside nested documents, arrays, arrays of subdocuments and to match a specific element of an array. @@ -299,6 +301,24 @@ db.find({ $or: [{ planet: 'Earth' }, { planet: 'Mars' }], inhabited: true }, fun ``` +#### Sorting and paginating +If you don't specify a callback to `find`, `findOne` or `skip`, a `Cursor` object is returned. You can modify the cursor with `sort`, `skip` and `limit` and then execute it with `exec(callback)`. + +```javascript +// Let's say the database contains these 4 documents +// doc1 = { _id: 'id1', planet: 'Mars', system: 'solar', inhabited: false, satellites: ['Phobos', 'Deimos'] } +// doc2 = { _id: 'id2', planet: 'Earth', system: 'solar', inhabited: true, humans: { genders: 2, eyes: true } } +// doc3 = { _id: 'id3', planet: 'Jupiter', system: 'solar', inhabited: false } +// doc4 = { _id: 'id4', planet: 'Omicron Persei 8', system: 'futurama', inhabited: true, humans: { genders: 7 } } + +// No query used means all results are returned (before the Cursor modifiers) +db.find({}).sort({ planet: 1 }).skip(1).limit(2).exec(function (err, docs) { + // docs is [doc3, doc1] +}); +``` + + + ### Counting documents You can use `count` to count documents. It has the same syntax as `find`. For example: @@ -314,6 +334,7 @@ db.count({}, function (err, count) { }); ``` + ### Updating documents `db.update(query, update, options, callback)` will update all documents matching `query` according to the `update` rules: * `query` is the same kind of finding query you use with `find` and `findOne`