extends layout block append style style. table td { padding-right: 15px; } block content h2 Migrating from 2.x to 3.x :markdown Migrating from Mongoose 2.x to 3.x brings with it [several changes](https://github.com/LearnBoost/mongoose/blob/master/History.md) to be aware of: h3 Query clean-up :markdown Many methods of the [Query](./api.html#query-js) API were nothing but aliases and have been [removed](https://github.com/LearnBoost/mongoose/commit/1149804c) in an effort to keep Mongoose clean and focused on there being as close to [one way](http://www.python.org/dev/peps/pep-0020/) of doing things as possible. If you really love all that extra noise, you can bring most of it back with [this module](https://github.com/aheckmann/mongoose-v2-compat). Here are the removed methods are their still existing aliases: table thead tr(style='text-align:left') th Removed th Alternative tbody tr td code query.run td code query.exec tr td code query.$or td code query.or tr td code query.$nor td code query.nor tr td code query.$gt td code query.gt tr td code query.$gte td code query.gte tr td code query.$lt td code query.lt tr td code query.$lte td code query.lte tr td code query.$ne td code query.ne tr td code query.$in td code query.in tr td code query.$nin td code query.nin tr td code query.$all td code query.all tr td code query.$regex td code query.regex tr td code query.$size td code query.size tr td code query.$maxDistance td code query.maxDistance tr td code query.$mod td code query.mod tr td code query.$near td code query.near tr td code query.$exists td code query.exists tr td code query.$elemMatch td code query.elemMatch tr td code query.$within td code query.within tr td code query.$box td code query.box tr td code query.$center td code query.center tr td code query.$centerSphere td code query.centerSphere tr td code query.$slice td code query.slice tr td code query.notEqualTo td code query.ne tr td code query.wherein td code query.within tr td code query.asc td code | query.sort a(href="#asc") * tr td code query.desc td code | query.sort a(href="#desc") * tr td code query.fields td code | query.select a(href="#fields") * h4#asc query#asc :markdown The `asc` method of [Query](./api.html#query-js) has been removed in favor of [sort](./api.html#query_Query-sort). The `sort` method accepts slightly different arguments so read the [docs](./api.html#query_Query-sort) to make sure your application is all set. h4#desc query#desc :markdown The `desc` method of [Query](./api.html#query-js) has been removed in favor of [sort](./api.html#query_Query-sort). The `sort` method accepts slightly different arguments so read the [docs](./api.html#query_Query-sort) to make sure your application is all set. h4#sort query#sort :markdown The [sort](./api.html#query_Query-sort) method of [Queries](./api.html#query-js) now accepts slightly different arguments. Read the [docs](./api.html#query_Query-sort) to make sure your application is all set. h4#fields query#fields :markdown The `fields` method of [Query](./api.html#query-js) has been removed, it being mostly an alias for the [select](./api.html#query_Query-select) method anyway. The `select` method has slightly different arguments so read the [docs](./api.html#query_Query-select) to make sure your application is all set. Because of the change to the `fields` method, the field selection argument for [query.populate](./api.html#query_Query-populate) and model methods like [findById](./api.html#model_Model-findById), [find](./api.html#model_Model-find), etc, is slightly different as well (no longer accepts arrays for example), so read the [docs](./api.html#query_Query-select) to make sure your application is all set. h3 Connecting to ReplicaSets :markdown To connect to a [ReplicaSet](http://www.mongodb.org/display/DOCS/Replica+Sets) you no longer use the separate `connectSet` or `createSetConnection` methods. Both [mongoose.connect](./api.html#index_Mongoose-connect) and [mongoose.createConnection](./api.html#index_Mongoose-createConnection) are now smart enough to just do the right thing with your connection string. If you really want to bring `connectSet` and `createSetConnection` back use [this module](https://github.com/aheckmann/mongoose-v2-compat). h3 Schemas :markdown - are now [strict](./guide.html#strict) by default. - Arrays of [object literal](./subdocs.html#altsyntax) now creates document arrays instead of arrays of [Mixed](./schematypes.html#mixed). - Indexes are now created in [background](./guide.html#autoIndex) by default. - Index errors are now emitted on their model instead of the connection. See issue [#984](https://github.com/LearnBoost/mongoose/issues/984). h3#arrays Arrays :markdown - [pop](./api.html#types_array_MongooseArray-pop) is now fixed causing a $set of the entire array. - [$pop](./api.html#types_array_MongooseArray-%24pop) is now fixed and behaves just as MongoDB [$pop](http://www.mongodb.org/display/DOCS/Updating#Updating-%24pop) does, removing at most the last element of the array. - [shift](./api.html#types_array_MongooseArray-shift) is now fixed causing a $set of the entire array. - [$shift](./api.html#types_array_MongooseArray-%24shift) is now fixed and behaves just as a [MongoDB $pop -1](http://www.mongodb.org/display/DOCS/Updating#Updating-%24pop) does, removing at most the first element of array. - `$unshift` was removed, use [unshift](./api.html#types_array_MongooseArray-unshift) instead. - `$addToSet` was removed, use [addToSet](./api.html#types_array_MongooseArray-addToSet) instead. - `$pushAll` was removed, use [push](./api.html#types_array_MongooseArray-push) instead. - `$pull` was removed, use [pull](./api.html#types_array_MongooseArray-pull) instead. - `$pullAll` was removed, use [pull](./api.html#types_array_MongooseArray-pull) instead. - `doAtomics` was changed to the [hasAtomics](./api.html#types_array_MongooseArray-hasAtomics) private method h3#mongoosenumber Number type :markdown The custom subclassed Number type Mongoose used to use for all numbers is now gone. It caused [too many problems](https://groups.google.com/d/msg/mongoose-orm/syKlN2xL1EE/FfRFhEFj4KcJ) when doing comparisons and had other bad side-effects. With it out of the picture, the following helper methods of MongooseNumbers are now also gone: - $inc - $increment - $decrement If you really want this behavior back, include the [mongoose-number](https://github.com/aheckmann/mongoose-number) module in your project. A good alternative is to start using the new [findAndModify](./api.html#model_Model-findOneAndUpdate) [helpers](./api.html#model_Model-findOneAndRemove). Say we have an inventory of 10 products and a customer purchases 7 of them. In Mongoose v2 you could have depended on MongooseNumber: :js var inventorySchema = new Schema({ productCount: Number }); ... Inventory.findById(id, function (err, inventory) { if (err) return handleError(err); inventory.productCount.$decrement(7); inventory.save(function (err) { // sends Inventory.update({ _id: id }, { $inc: { balance: -7 }}, callback); if (err) return handleError(err); res.send(inventory.productCount); // 3 }); }); :markdown With MongooseNumber out of the picture, we'll instead use the [Account.findByIdAndUpdate](./api.html#model_Model-findByIdAndUpdate) helper: :js Inventory.findByIdAndUpdate(id, { $inc: { productCount: -7 }}, function (err, inventory) { if (err) return handleError(err); res.send(inventory.productCount); // 3 }); :markdown The `findByIdAndUpdate` helper not only finds the document but updates it as well before responding with the altered document. The findAndModify helpers are a great addition for many use cases. h3#documents Documents :markdown - `doc#commit` is now removed, use [doc.markModified](./api.html#document_Document-markModified) instead - [doc#modifiedPaths](./api.html#document_Document-modifiedPaths) is now a method not a getter - `doc.modified` is now removed, use [doc.isModified](./api.html#document_Document-isModified) instead h4#gettercasting getter casting :markdown Getters no longer apply casting. Casting happens at set time. Useful in situations where you desire formatted responses like currency. See issue [#820](https://github.com/LearnBoost/mongoose/issues/820) and pull [#924](https://github.com/LearnBoost/mongoose/pull/924). h4#setterorder setter order :markdown Values being set no longer cast until _after_ all setters have been applied. Previously the value returned from each setter was cast _before_ passing it on to the next setter. This changes allows more flexible processing of values in setters. See issue [#665](https://github.com/learnboost/mongoose/issues/665) and pull [#924](https://github.com/LearnBoost/mongoose/pull/924). h3#subdocs Subdocuments :markdown - `subdoc.parent` was changed from a property to a [method](./api.html#types_embedded_EmbeddedDocument-parent). See issue [#928](https://github.com/LearnBoost/mongoose/issues/928). - `subdoc.parentArray` was changed from a property to a [method](./api.html#types_embedded_EmbeddedDocument-parentArray). See issue [#928](https://github.com/LearnBoost/mongoose/issues/928). h3#stringmatch String match validator :markdown The String SchemaType [match](./api.html#schema_string_SchemaString-match) validator no longer checks against null, undefined, or ''. If you need to validate against these values, enable the [required](./api.html#schematype_SchemaType-required) validator as well. See issue [#934](https://github.com/LearnBoost/mongoose/issues/934) and pull request [#935](https://github.com/LearnBoost/mongoose/pull/935). h3#version Versioning :markdown Documents are now transparently versioned. Read the in depth details [here](http://aaronheckmann.posterous.com/tag/versioning).