From 66b81a18b8270741cf277d9aeb948f90af17aba9 Mon Sep 17 00:00:00 2001 From: Louis Chatriot Date: Thu, 16 May 2013 17:22:59 +0200 Subject: [PATCH] Update README.md --- README.md | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/README.md b/README.md index 9f37698..5a01e22 100644 --- a/README.md +++ b/README.md @@ -76,6 +76,10 @@ db.find({ system: 'solar', inhabited: true }, function (err, docs) { // docs is an array containing document _id2 only }); +db.find({}, function (err, docs) { + // docs contains all documents in the collection +}); + db.findOne({ _id: 'id1' }, function (err, doc) { // doc is the document _id1 // If no document is found, doc is null @@ -87,7 +91,7 @@ db.findOne({ _id: 'id1' }, function (err, doc) { * `query` is the same kind of finding query you use with `find` and `findOne` * `update` specifies how the documents should be modified. It is either a new document or a set of modifiers (you cannot use both together, it doesn't make sense!) * A new document will replace the matched docs - * The available modifiers are `$set` to change a field's value and `$inc` to increment a field's value. The modifiers create the fields they need to modify if they don't exist, and you can apply them to subdocs (see examples below) + * The available modifiers are `$set` to change a field's value and `$inc` to increment a field's value. The modifiers create the fields they need to modify if they don't exist, and you can apply them to subdocs. See examples below for the syntax * `options` is an object with two possible parameters * `multi` (defaults to `false`) which allows the modification of several documents if set to true * `upsert` (defaults to `false`) if you want to insert a new document corresponding to the `update` rules if your `query` doesn't match anything @@ -98,17 +102,32 @@ db.findOne({ _id: 'id1' }, function (err, doc) { ```javascript // Let's use the same example collection as in the "finding document" part +// Replace a document by another db.update({ planet: 'Jupiter' }, { planet: 'Pluton'}, {}, function (err, numReplaced) { // numReplaced = 1 // The doc #3 has been replaced by { _id: 'id3', planet: 'Pluton' } // Note that the _id is kept unchanged, and the document has been replaced - // (the 'system' field is not here anymore) + // (the 'system' and inhabited fields are not here anymore) }); -db.update({ system: 'solar' }, { $set: { system: 'solar system' } }, { multi: true }, function (err, numResult) { - // numResult = 3 +// Set an existing field's value +db.update({ system: 'solar' }, { $set: { system: 'solar system' } }, { multi: true }, function (err, numReplaced) { + // numReplaced = 3 // Field 'system' on Mars, Earth, Jupiter now has value 'solar system' }); + +// Incrementing the value of a non-existing field in a subdocument +db.update({ planet: 'Mars' }, { $inc: { "data.satellites": 2 } }, {}, function () { + // Mars document now is { _id: 'id1', system: 'solar', inhabited: false + // , data: { satellites: 2 } + // } +}); + +// Upserting a document +db.update({ planet: 'Pluton' }, { planet: 'Pluton', inhabited: false }, { upsert: true }, function (err, numReplaced, upsert) { + // numReplaced = 1, upsert = true + // A new document { _id: 'id5', planet: 'Pluton', inhabited: false } has been added to the collection +}); ```