Above we’ve defined the query conditions in the find() method. We can also do this using a where() function, and we can chain all the parts of our query together using the dot operator (.) rather than adding them separately. The code fragment below is the same as our query above, with an additional condition for the age.
We will write the model for a Genealogy app, a Person with a few personal properties, including who their parents are. We’ll also see how we can use this model to create and modify Persons and save them to MongoDB. NoSQL brought flexibility to the tabular world of databases. MongoDB in particular became an excellent option to store unstructured JSON documents. Data starts as JSON in the UI and undergoes very few transformations to be stored, so we get benefits from increased performance and decreased processing time.
The benefit of using Mongoose is that we have a schema to work against in our application code and an explicit relationship between our MongoDB documents and the Mongoose models within our application. The downside is that we can only create blog posts and they have to follow the above defined schema. If we change our Mongoose schema, we are changing the relationship completely, and if you’re going through rapid development, this can greatly slow you down. Once you’ve created a schema you can use it to create models. The model represents a collection of documents in the database that you can search, while the model’s instances represent individual documents that you can save and retrieve.
Anything outside of the defined fields, will also not be inserted in the database. The Schema allows you to define the fields stored in each document along with their validation requirements and default values. We can choose between two different ways of adding schema validation to our MongoDB collections. The first is to use application-level validators, which are defined in the schwinn bicycles schemas. The second is to use MongoDB schema validation, which is defined in the MongoDB collection itself.
As discussed in the primer above, this code creates the default connection to the database and binds to the error event . Open a command prompt and navigate to the directory where you created your skeleton Local Library website. Enter the following command to install Mongoose and add it to your package.json file, unless you have already done so when reading the Mongoose Primer above.
Field name and type as a key-value pair (i.e. as done with fields name, binary and living). We know that we need to store information about books and that we might have multiple copies available (with globally unique ids, availability statuses, etc.). We might need to store more information about the author than just their name, and there might be multiple authors with the same or similar names. We want to be able to sort information based on the book title, author, genre, and category.